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# Boiler Spares 

## Sitemaps

- [XML Sitemap](https://boilerandspares.co.uk/sitemap.xml): Contains all public & indexable URLs for this website.

## Posts

- [Blog](https://boilerandspares.co.uk/blog/) - Browse the Boiler Spares blog for clear heating advice, parts guidance and practical fixes. Read expert posts and choose the right next article.
- [Why Is My Boiler Making a Banging Noise? Is it Kettling ?](https://boilerandspares.co.uk/why-is-my-boiler-making-a-banging-noise-is-it-kettling/) - A boiler that makes a banging noise may be suffering from kettling, a fault caused by limescale, sludge, or restricted water flow overheating the heat exchanger. Kettling often produces rumbling, knocking, or whistling sounds, but banging can also point to trapped air, pump problems, or pressure issues. This article explains the main causes, the signs
- [Why Your Boiler Cuts Out After a Few Minutes](https://boilerandspares.co.uk/why-your-boiler-cuts-out-after-a-few-minutes/) - If a boiler cuts out after a few minutes, it is usually reacting to a fault signal from one of its built-in safety sensors. The shutdown is a protective response, not a random failure. Common causes include low boiler pressure, a blocked condensate pipe, a faulty flame sensor, or overheating. This article explains each cause,
- [Diverter Valves Explained: Why They Fail and What Replacement Costs](https://boilerandspares.co.uk/diverter-valves-explained-why-they-fail-and-what-replacement-costs/) - Inside a combi boiler, the diverter valve sends hot water either to the heating circuit or to the domestic hot water taps, depending on demand. When it fails, the boiler cannot prioritise correctly, which can leave households with no hot water or no heating. This article explains how diverter valves work, the most common failure
- [Plumbing Maintenance Checklist: Prevent Leaks, Blockages, and Water Damage](https://boilerandspares.co.uk/plumbing-maintenance-checklist-prevent-leaks-blockages-and-water-damage/) - Reduce leaks, blockages and water damage with a plumbing checklist covering monthly, quarterly, annual and winter checks.
- [Gas Boiler Safety: Carbon Monoxide Risks, Warning Signs, and Detectors](https://boilerandspares.co.uk/gas-boiler-safety-carbon-monoxide-risks-warning-signs-and-detectors/) - See 5 gas boiler carbon monoxide warning signs, how faulty combustion causes CO, and how alarms and maintenance cut poisoning risk.
- [Radiator Not Heating Up? Bleeding, Balancing, and Boiler-Related Causes](https://boilerandspares.co.uk/radiator-not-heating-up-bleeding-balancing-and-boiler-related-causes/) - Learn why a radiator stays cold, how to bleed and balance it safely, and when low pressure, sludge or pump faults need attention
- [Drain Unblocking: Causes of Slow Drains and When to Call a Plumber](https://boilerandspares.co.uk/drain-unblocking-causes-of-slow-drains-and-when-to-call-a-plumber/) - Spot 7 warning signs of a blocked drain, learn quick checks that show the cause, and know when a plumber can prevent leaks and damage
- [Complete Guide to Boiler and Plumbing](https://boilerandspares.co.uk/complete-guide-to-boiler-and-plumbing/) - See how UK boiler and plumbing systems work, compare boiler types, spot common faults, save water, and know when to call an engineer
- [Hard Water Problems in Plumbing & How to Fix Them](https://boilerandspares.co.uk/hard-water-problems-in-plumbing-how-to-fix-them/) - See how hard water causes limescale, low pressure and boiler wear, plus 5 fixes including descaling, water softeners and testing.
- [Smart Thermostats vs. Old School Controllers — Which Wins?](https://boilerandspares.co.uk/smart-thermostats-vs-old-school-controllers-which-wins/) - Compare smart thermostats with old controllers in 2026 and see how they differ on costs, comfort, control, privacy and long-term value.
- [We Asked 15 Engineers: What’s the Most Common Boiler Fault?](https://boilerandspares.co.uk/we-asked-15-engineers-whats-the-most-common-boiler-fault/) - See which boiler fault 15 engineers report most, the warning signs to spot, likely causes and the safety checks to take first.
- [Boiler vs. Heat Pump: Which Is Right for Your Home in 2026?](https://boilerandspares.co.uk/boiler-vs-heat-pump-which-is-right-for-your-home/) - Compare boilers and heat pumps for UK homes in 2026, with costs, payback, grants, insulation needs and which suits your property.
- [The Shocking Truth About Boiler Lifespans — And When You Should Replace Yours](https://boilerandspares.co.uk/the-shocking-truth-about-boiler-lifespans-and-when-you-should-replace-yours/) - See how long boilers usually last by type, what shortens service life, and when repair costs, breakdowns and bills signal replacement.
- [Boiler Maintenance Secrets Technicians Don’t Want You to Know](https://boilerandspares.co.uk/boiler-maintenance-secrets-technicians-dont-want-you-to-know/) - Spot 7 early boiler faults, from low pressure to blocked condensate pipes, and learn safe checks that cut breakdowns and energy waste.
- [How to Slash Your Heating Bills Without Freezing This Winter](https://boilerandspares.co.uk/how-to-slash-your-heating-bills-without-freezing-this-winter/) - Cut winter heating bills with 5 practical tips on thermostats, insulation, draught-proofing and boiler efficiency while keeping rooms warm

## Pages

- [Home Page](https://boilerandspares.co.uk/) - Receive a plain-English diagnosis, a step-by-step repair guide, and direct links to the exact replacement parts you need.
- [Cookie Policy](https://boilerandspares.co.uk/cookie-policy/) - See which cookies Boiler Spares uses, why they are needed, and how they support site performance and analytics. Review cookie details now.
- [Terms of Service](https://boilerandspares.co.uk/terms-of-service/) - Read the Boiler Fault Finder terms, safety disclaimer and accuracy limits before using free fault code guidance. Review the terms now.
- [Privacy Policy](https://boilerandspares.co.uk/privacy-policy/) - See how Boiler & Spares Ltd collects and uses contact form and website data, with clear details on your rights and how to contact us.
- [Gas Safety Guide](https://boilerandspares.co.uk/gas-safety/) - Get clear gas safety advice for boilers and appliances, with practical checks and warning signs. Read the guide and stay safe.
- [Contact](https://boilerandspares.co.uk/contact/) - Need boiler spares or advice? Contact Boiler Spares for fast, expert help with parts enquiries and support. Call, email or send a message.
- [About](https://boilerandspares.co.uk/about/) - Find Boiler Spares' company story, expertise and service standards, so you can buy parts with confidence. See who we are.
- [FAQ](https://boilerandspares.co.uk/faq/) - Get clear answers on boiler spares, compatibility, delivery and returns. Save time with practical FAQs, then check the guidance.
- [How it works](https://boilerandspares.co.uk/how-it-works/) - See how Boiler Spares works, from finding the right part to fast ordering and delivery. Follow the simple steps and place your order.
- [Engineer Portal](https://boilerandspares.co.uk/engineer-portal/) - Access the Boiler Spares engineer portal for trade pricing, fast parts lookup and account tools. Sign in to order the right spares.
- [Browse All Brands](https://boilerandspares.co.uk/browse-all-brands/) - View every boiler brand stocked by Boiler Spares in one place, with quick access to parts by make. Browse the catalogue and choose your brand.

## Boiler Brands

- [Myson](https://boilerandspares.co.uk/brands/myson/) - Source Myson boiler spares for Marathon and Apollo models, including hard-to-find parts for older boilers. Check compatible parts now.
- [Sime](https://boilerandspares.co.uk/brands/sime/) - Check Sime boiler error codes for UK models, including AL and E alarms across key ranges. Identify faults fast and match the right code.
- [Chaffoteaux](https://boilerandspares.co.uk/brands/chaffoteaux/) - Get Chaffoteaux boiler and spare parts information, including Britony, Celtic, Pigma and Mira details. Check models and fault code links.
- [Warmflow](https://boilerandspares.co.uk/brands/warmflow/) - Buy Warmflow oil-fired condensing boilers and cylinders for homes without mains gas, with trusted parts support across Ireland and the rural UK. Browse now.
- [Halstead](https://boilerandspares.co.uk/brands/halstead/) - Source Halstead boiler spares for Ace, Eden, Finest and Hero models, including hard-to-find parts. Check the catalogue and order the right item.
- [Hamworthy](https://boilerandspares.co.uk/brands/hamworthy/) - Source Hamworthy commercial and light-commercial boiler, water heater and heating system spares for fast UK supply. Browse parts now.
- [Firebird](https://boilerandspares.co.uk/brands/firebird/) - Browse Firebird oil and gas condensing boilers from Boiler Spares, trusted in rural UK and Ireland for robust, efficient heating. View the range.
- [ATAG](https://boilerandspares.co.uk/brands/atag/) - ATAG boiler fault codes explained, plus IC and IS boiler range details. Check common code formats and identify the right boiler parts.
- [Remeha](https://boilerandspares.co.uk/brands/remeha/) - See Remeha boiler ranges, including Avanta and Calenta, with key features, compact designs and reliable performance. Compare options now.
- [Johnson & Starley](https://boilerandspares.co.uk/brands/johnson-starley/) - Buy Johnson & Starley boiler spares and heating parts for warm air systems, heat pumps and Aquastar boilers. Check the range now.
- [Heatline](https://boilerandspares.co.uk/brands/heatline/) - See Heatline Capriz and Capriz Plus fault codes with Vaillant-related F-code meanings for faster diagnosis. Check the guide now.
- [Grant](https://boilerandspares.co.uk/brands/grant/) - See Grant oil-fired boilers at a glance, including the Vortex condensing range and OFTEC repair requirements. Check Grant details now.
- [Biasi](https://boilerandspares.co.uk/brands/biasi/) - Get Biasi boiler fault codes and model information, including Riva boilers, with clear letter-and-number explanations. Check your boiler now.
- [Navien](https://boilerandspares.co.uk/brands/navien/) - Navien is a South Korean heating technology company founded in 1978. Known for innovative condensing combi boilers with stainless steel heat exchangers, their NCB series is increasingly popular in the…
- [Ravenheat](https://boilerandspares.co.uk/brands/ravenheat/) - Ravenheat is an Italian boiler manufacturer whose products are popular in the UK social housing sector. Their CSI, CS, WH, and HE ranges are commonly found in flats and council…
- [Saunier Duval](https://boilerandspares.co.uk/brands/saunier-duval/) - Saunier Duval is a French heating brand founded in 1924, part of the Vaillant Group since 2003. Popular in France and Southern Europe, their boilers share significant technology with Vaillant.…
- [Keston](https://boilerandspares.co.uk/brands/keston/) - Keston is a premium British condensing boiler brand founded in 1948. Known for highly efficient, side-flue boilers that don't require a traditional flue, Keston boilers are popular where conventional fluing…
- [Main Heating](https://boilerandspares.co.uk/brands/main-heating/) - Main Heating is a UK boiler brand that is part of BDR Thermea, the same group as Baxi and Potterton. Their boilers share many components and fault codes with Baxi.…
- [Intergas](https://boilerandspares.co.uk/brands/intergas/) - Intergas is a Dutch heating company founded in 1964, known for producing innovative, highly reliable boilers with a simplified single heat exchanger design. The Intergas HRE and Rapid ranges are…
- [Vokera](https://boilerandspares.co.uk/brands/vokera/) - Vokera is a British boiler manufacturer based in Hertfordshire, founded in 1985. Known for producing reliable, affordable combi and system boilers, they are popular in the UK rental market. Vokera…
- [Ariston](https://boilerandspares.co.uk/brands/ariston/) - Ariston is an Italian heating brand founded in 1960, part of the Ariston Thermo Group. Their boilers are popular across Europe for their stylish design and reliable performance. Ariston fault…
- [Viessmann](https://boilerandspares.co.uk/brands/viessmann/) - Viessmann is a German heating technology company founded in 1917. Known for producing premium, highly efficient boilers, their Vitodens range is popular in the UK for its exceptional reliability and…
- [Ferroli](https://boilerandspares.co.uk/brands/ferroli/) - Ferroli is an Italian heating manufacturer with over 60 years of experience, founded in Verona in 1955. Their boilers are well-regarded for quality engineering and are popular across Europe. In…
- [Alpha](https://boilerandspares.co.uk/brands/alpha/) - Alpha Heating Innovation is a UK-based boiler manufacturer known for producing reliable, competitively priced gas boilers. Their E-Tec, InTec, and CB range are popular choices for both new installations and…
- [Potterton](https://boilerandspares.co.uk/brands/potterton/) - Potterton is one of the UK's oldest heating brands, founded in 1850 by Thomas Potterton in London. The company completed its first gas boiler installation in 1902 and has been…
- [Glow-worm](https://boilerandspares.co.uk/brands/glow-worm/) - Glow-worm is a well-established British boiler brand with over 80 years of history, founded in Derbyshire in 1934. Since 2001, the company has been part of the Vaillant Group, which…
- [Ideal](https://boilerandspares.co.uk/brands/ideal/) - Ideal Heating has been manufacturing boilers in Hull since 1906 and is one of the UK's largest domestic boiler brands. Their Logic, Logic+, and Vogue ranges are extremely popular. Ideal…
- [Baxi](https://boilerandspares.co.uk/brands/baxi/) - Baxi is a British boiler brand founded in Bolton in 1866, making it one of the oldest heating manufacturers in the UK. Today they are part of the BDR Thermea…
- [Worcester Bosch](https://boilerandspares.co.uk/brands/worcester-bosch/) - Worcester Bosch is one of the UK's most trusted boiler brands, having been established in 1962. Their Greenstar range is installed in over 1 in 3 UK homes, making them…
- [Vaillant](https://boilerandspares.co.uk/brands/vaillant/) - One of Europe's leading boiler manufacturers, Vaillant has been producing heating systems since 1874. Their ecoTEC range is among the most popular in the UK, known for high efficiency and…

## Fault Codes

- [Sime AL 24 - Flow Sensor Short (Alarm 24)](https://boilerandspares.co.uk/fault-codes/sime-al-24/) - Fix Sime AL 24 short alarm 24 flow sensor faults with clear code meaning, likely causes and spare part guidance. Check the remedy.
- [Sime AL 25 - DHW Sensor Short (Alarm 25)](https://boilerandspares.co.uk/fault-codes/sime-al-25/) - Clear explanation of the Sime AL 25 DHW sensor short alarm, with likely causes and practical checks. See the fault code steps now.
- [Sime AL 27 - Compatibility Error (Alarm 27)](https://boilerandspares.co.uk/fault-codes/sime-al-27/) - Fix Sime AL 27 compatibility error alarm 27 with fault code guidance, likely causes and parts help from Boiler Spares. Check the remedy.
- [Sime AL 29 - PCB Fault (Alarm 29)](https://boilerandspares.co.uk/fault-codes/sime-al-29/) - Fix Sime AL 29 PCB fault Alarm 29 with boiler repair help, clear fault guidance and compatible spares. Check the symptoms and parts.
- [Sime AL 31 - Communication Fault (Alarm 31)](https://boilerandspares.co.uk/fault-codes/sime-al-31/) - Fix Sime AL 31 communication fault alarm 31 with clear fault-code guidance, likely causes and parts help. Check the fault and order spares.
- [Sime AL 32 - Combustion Fault (Alarm 32)](https://boilerandspares.co.uk/fault-codes/sime-al-32/) - Clear guide to Sime AL 32 combustion fault alarm 32, with likely causes and practical checks to help you diagnose the issue. See the steps.
- [Sime E01 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/sime-e01/) - Understand Sime E01 ignition failure code, its likely causes and fixes, with clear fault guidance and parts help. Check your boiler next.
- [Sime E02 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/sime-e02/) - Fix Sime E02 overheat protection fault codes with clear causes, checks and parts guidance from Boiler Spares. Identify the fault and order parts.
- [Sime E03 - Fan Fault](https://boilerandspares.co.uk/fault-codes/sime-e03/) - Understand Sime E03 fan fault codes, common causes and practical fixes with clear troubleshooting steps. Check symptoms and parts.
- [Sime E04 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/sime-e04/) - See what Sime E04 means, the likely DHW sensor fault causes, and parts advice from Boiler Spares. Check the code and order the right part.
- [Sime E05 - Flow Sensor Fault](https://boilerandspares.co.uk/fault-codes/sime-e05/) - Understand the Sime E05 flow sensor fault, common causes and fixes, with clear troubleshooting steps and parts guidance. Check yours now.
- [Sime E06 - No Flame Detection](https://boilerandspares.co.uk/fault-codes/sime-e06/) - Fix Sime E06 no flame detection faults with clear checks, likely causes and spare part guidance. Diagnose the issue and order parts.
- [Sime E07 - Safety Thermostat Intervention](https://boilerandspares.co.uk/fault-codes/sime-e07/) - Fix Sime E07 safety thermostat faults with clear code guidance, likely causes and spare parts help. Identify the issue and order the right part.
- [Sime E08 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/sime-e08/) - Fix Sime E08 air pressure switch faults with clear checks, likely causes and parts guidance from Boiler Spares. Identify the issue fast.
- [Sime E09 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/sime-e09/) - Troubleshoot Sime E09 gas valve faults with clear causes, checks and fix options. Identify the issue faster and see the next steps.
- [Sime E10 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/sime-e10/) - Understand the Sime E10 return sensor fault, common causes and fixes, with clear guidance to diagnose the issue and order the right part.
- [Sime E11 - PCB Fault](https://boilerandspares.co.uk/fault-codes/sime-e11/) - Understand Sime E11 PCB fault codes fast with clear causes, checks and parts guidance from Boiler Spares. Fix the issue with the right next step.
- [Sime E12 - Pump Fault](https://boilerandspares.co.uk/fault-codes/sime-e12/) - See what the Sime E12 fault means, common causes and the parts often linked to it. Use our guide to identify the issue and order spares.
- [Sime E13 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/sime-e13/) - Fix Sime E13 low water pressure faults with clear checks, likely causes and parts guidance. Identify the issue fast and view spares.
- [Sime E14 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/sime-e14/) - Fix a Sime E14 condensate blocked fault with clear fault-code advice, likely causes and parts guidance. Check symptoms and next steps.
- [Sime E15 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/sime-e15/) - Understand the Sime E15 diverter valve fault, common causes and repair options. Identify the issue fast and order the right boiler spares.
- [Sime E16 - Flame Lost During Operation](https://boilerandspares.co.uk/fault-codes/sime-e16/) - Fix Sime E16 flame lost during operation with clear fault checks, likely causes and parts guidance from Boiler Spares. See the steps.
- [Sime AL 01 - Smoke Thermostat (Alarm 01)](https://boilerandspares.co.uk/fault-codes/sime-al-01/) - Fix Sime AL 01 smoke thermostat faults with clear checks, likely causes and part guidance. Identify the issue fast and order the right spares.
- [Sime AL 02 - Low Water Pressure (Alarm 02)](https://boilerandspares.co.uk/fault-codes/sime-al-02/) - Get a clear explanation of Sime AL 02 low water pressure alarm 02, with likely causes and parts guidance. Check the fault and order spares.
- [Sime AL 04 - DHW Sensor Fault (Alarm 04)](https://boilerandspares.co.uk/fault-codes/sime-al-04/) - Fix Sime AL 04 DHW sensor fault Alarm 04 with clear checks, likely causes and spare parts guidance. Identify the issue and order parts.
- [Sime AL 05 - Flow Sensor Fault (Alarm 05)](https://boilerandspares.co.uk/fault-codes/sime-al-05/) - Fix Sime AL 05 flow sensor fault alarm 05 with clear fault advice, likely causes and matching boiler spares. Check symptoms and order parts.
- [Sime AL 06 - No Flame Detection (Alarm 06)](https://boilerandspares.co.uk/fault-codes/sime-al-06/) - Fix Sime AL 06 no flame detection alarm 06 fast with fault code guidance and compatible boiler spares. Check symptoms and order parts.
- [Sime AL 07 - Safety Thermostat (Alarm 07)](https://boilerandspares.co.uk/fault-codes/sime-al-07/) - Fix Sime AL 07 safety thermostat faults with clear code checks, likely causes and repair steps. Use the guide to diagnose the issue.
- [Sime AL 09 - Fan Fault (Alarm 09)](https://boilerandspares.co.uk/fault-codes/sime-al-09/) - Fix Sime AL 09 fan fault alarm 09 with clear checks, likely causes and parts advice from Boiler Spares. See the guide and order spares.
- [Sime AL 10 - Return Sensor Fault (Alarm 10)](https://boilerandspares.co.uk/fault-codes/sime-al-10/) - Fix Sime AL 10 return sensor fault alarm 10 with clear fault guidance and genuine Boiler Spares parts. Check symptoms and order the right part.
- [Chaffoteaux 50 - Ionisation PCB Fault (LED code)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-50/) - Fix Chaffoteaux fault 50 with clear LED code guidance, likely PCB and ionisation causes, and matching boiler spares. Check parts now.
- [Chaffoteaux 60 - Antifrost Mode — Pump Running (LED code)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-60/) - See what the Chaffoteaux 60 antifrost mode pump running LED code means, common causes and fixes, then check the right boiler spares.
- [Chaffoteaux 70 - Antifrost Mode — Burner Running (LED code)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-70/) - See what the Chaffoteaux 70 antifrost mode burner running LED code means, likely causes and parts advice, then identify the right fix.
- [Chaffoteaux 80 - DHW Thermistor Open Circuit (LED code)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-80/) - Fix the Chaffoteaux 80 DHW thermistor open circuit LED code with fault causes, checks and part guidance. Identify the issue and order spares.
- [Chaffoteaux E01 - Ignition Failure (modern models)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-e01/) - Fix Chaffoteaux E01 ignition failure on modern models with clear fault code checks and likely causes. See the steps and order parts.
- [Chaffoteaux E02 - Safety Thermostat (modern models)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-e02/) - Fix Chaffoteaux E02 safety thermostat faults on modern models with clear causes and parts guidance. Check the code and order spares.
- [Chaffoteaux E03 - Low Pressure (modern models)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-e03/) - Fix Chaffoteaux E03 low pressure faults on modern models with clear checks and parts guidance. Identify the cause and order the right spares.
- [Chaffoteaux E04 - Flow Sensor Fault (modern models)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-e04/) - Fix a Chaffoteaux E04 flow sensor fault on modern boilers with clear causes, checks and part guidance. Identify the issue and act fast.
- [Chaffoteaux E05 - Return Sensor Fault (modern models)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-e05/) - Fix Chaffoteaux E05 return sensor faults on modern boilers with clear checks, likely causes and parts guidance. Identify the issue now.
- [Myson PILOT OUT - Pilot Light Failure](https://boilerandspares.co.uk/fault-codes/myson-pilot-out/) - Get clear fixes for the Myson PILOT OUT fault code, covering pilot light failure causes, likely parts and repair steps. Check solutions now.
- [Myson FLUE SPILLAGE - Flue Spillage Detector Tripped](https://boilerandspares.co.uk/fault-codes/myson-flue-spillage/) - Fix a Myson flue spillage detector tripped fault code with clear checks, likely causes and spare parts guidance. See the fault steps.
- [Myson OVERHEAT - High Temperature Lockout](https://boilerandspares.co.uk/fault-codes/myson-overheat/) - Get Myson OVERHEAT high temperature lockout fault code help, with clear causes and fixes for faster diagnosis. Check the guidance now.
- [Myson NO IGNITION - Main Burner Not Lighting](https://boilerandspares.co.uk/fault-codes/myson-no-ignition/) - Fix a Myson boiler with no ignition or main burner not lighting using fault guidance and matching spares. Check symptoms and order parts.
- [Myson PUMP FAULT - Pump Not Running](https://boilerandspares.co.uk/fault-codes/myson-pump-fault/) - Fix a Myson PUMP FAULT where the pump is not running with clear fault guidance and matching Boiler Spares parts. Check the fix now.
- [Myson LOW PRESSURE - Low System Pressure](https://boilerandspares.co.uk/fault-codes/myson-low-pressure/) - Understand the Myson LOW PRESSURE fault code, what causes it and how to fix it with clear steps. Check the fault and order the right spares.
- [Halstead 13 - Pump Fault](https://boilerandspares.co.uk/fault-codes/halstead-13/) - Get the Halstead 13 pump fault code explained with likely causes, practical checks and the right boiler spares. See the fault details now.
- [Halstead 14 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/halstead-14/) - See what the Halstead 14 fault code means when condensate is blocked, with likely causes and practical checks. Identify the fix.
- [Halstead 15 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/halstead-15/) - Get clear fixes for the Halstead 15 flue gas overheat fault code, with likely causes and parts guidance. Check the fault and order spares.
- [Chaffoteaux 501 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/chaffoteaux-501/) - Fix Chaffoteaux 501 ignition failures with clear fault checks and parts guidance from Boiler Spares. Identify the cause and order spares.
- [Chaffoteaux 101 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/chaffoteaux-101/) - Fix Chaffoteaux 101 overheat protection fault code with clear causes, checks and parts advice. Identify the fault fast and order spares.
- [Chaffoteaux 103 - Poor Circulation / Flow Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-103/) - Fix Chaffoteaux 103 poor circulation flow faults with clear causes, part checks and compatible spares. View the fault guide now.
- [Chaffoteaux 108 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/chaffoteaux-108/) - Fix the Chaffoteaux 108 low water pressure fault with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Chaffoteaux 110 - Flow Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-110/) - Fix a Chaffoteaux 110 flow temperature sensor fault with clear checks, likely causes and spare part guidance. Identify the issue now.
- [Chaffoteaux 112 - Return Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-112/) - Fix Chaffoteaux 112 return temperature sensor faults with clear checks, likely causes and parts guidance. Identify the issue and order the right spare.
- [Chaffoteaux 301 - Flue/Combustion Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-301/) - Fix a Chaffoteaux 301 flue/combustion fault with clear cause checks and parts guidance from Boiler Spares. Identify the issue and order.
- [Chaffoteaux 304 - Fan Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-304/) - Understand the Chaffoteaux 304 fan fault, common causes and checks, with clear guidance to identify the issue and order the right part.
- [Chaffoteaux 604 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-604/) - Fix Chaffoteaux 604 air pressure switch faults with clear checks, likely causes and matching boiler spares. Identify the issue fast.
- [Chaffoteaux 607 - Fan/Flue Airflow Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-607/) - Fix Chaffoteaux 607 fan/flue airflow faults with clear code meanings, likely causes and parts guidance. Check the 607 fault details now.
- [Chaffoteaux 610 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/chaffoteaux-610/) - See what a Chaffoteaux 610 DHW sensor fault means, common causes and likely fixes, with plain-English guidance. Check the fault code.
- [Chaffoteaux 15 - Overheat Sensor Open (LED code)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-15/) - Fix the Chaffoteaux 15 overheat sensor open LED code with clear fault checks, likely causes and parts guidance. Identify the issue fast.
- [Chaffoteaux 30 - Overheating Without Lockout (LED code)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-30/) - Fix a Chaffoteaux 30 overheating fault without a lockout LED code with clear checks, likely causes and parts guidance. View the steps.
- [Chaffoteaux 40 - No Flame Detection (LED code)](https://boilerandspares.co.uk/fault-codes/chaffoteaux-40/) - Fix Chaffoteaux 40 no flame detection LED faults with clear code checks, likely causes and parts guidance. Identify the fault fast.
- [Halstead 1 - Ignition Lockout](https://boilerandspares.co.uk/fault-codes/halstead-1/) - Fix the Halstead 1 ignition lockout fault code with clear fault checks, likely causes and boiler spares advice. See the steps now.
- [Halstead 2 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/halstead-2/) - Fix a Halstead 2 overheat lockout fault code with clear fault causes, part checks and boiler spares advice. See the troubleshooting steps.
- [Halstead 3 - Fan / Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/halstead-3/) - Fix the Halstead 3 fan/air pressure switch fault with clear causes, part guidance and practical checks. Identify the right next step.
- [Halstead 4 - Flame Loss During Operation](https://boilerandspares.co.uk/fault-codes/halstead-4/) - Get the Halstead 4 flame loss during operation fault code explained with likely causes and matching Boiler Spares parts. Check the fix now.
- [Halstead 5 - Return Thermistor Fault](https://boilerandspares.co.uk/fault-codes/halstead-5/) - Fix a Halstead 5 return thermistor fault with clear fault code guidance, likely causes and parts support. Check the code and order spares.
- [Halstead 6 - Flow Thermistor Fault](https://boilerandspares.co.uk/fault-codes/halstead-6/) - See what the Halstead 6 flow thermistor fault code means, common causes and likely fixes, with clear fault guidance. Check the code now.
- [Halstead 7 - DHW Thermistor Fault](https://boilerandspares.co.uk/fault-codes/halstead-7/) - Fix the Halstead 7 DHW thermistor fault code with clear causes, checks and parts guidance from Boiler Spares. Identify the issue now.
- [Halstead 8 - PCB / Electronics Fault](https://boilerandspares.co.uk/fault-codes/halstead-8/) - Halstead 8 PCB/electronics fault explained with likely causes and boiler spares guidance. Check the fault details and order the right part.
- [Halstead 9 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/halstead-9/) - Understand the Halstead 9 gas valve fault code, common causes and fixes, with clear guidance to diagnose the issue and order the right part.
- [Halstead 10 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/halstead-10/) - Fix the Halstead 10 diverter valve fault code with clear fault checks, likely causes and parts guidance. Identify the issue and order spares.
- [Halstead 11 - Differential Check Failure](https://boilerandspares.co.uk/fault-codes/halstead-11/) - Halstead 11 differential check failure fault code explained with likely causes and boiler spare guidance. Check symptoms and identify parts.
- [Halstead 12 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/halstead-12/) - Fix the Halstead 12 low water pressure fault code with clear checks, likely causes and parts guidance. See the steps and order spares.
- [Firebird L2 - Flame Failure During Operation](https://boilerandspares.co.uk/fault-codes/firebird-l2/) - Fix Firebird L2 flame failure during operation with clear fault checks, likely causes and parts guidance. See the steps and order spares.
- [Firebird L3 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/firebird-l3/) - Fix the Firebird L3 overheat lockout fault code with clear causes, checks and parts guidance from Boiler Spares. See the fault steps.
- [Firebird L4 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/firebird-l4/) - Fix a Firebird L4 low water pressure fault with clear checks, likely causes and parts advice. Identify the issue fast and order spares.
- [Firebird L5 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/firebird-l5/) - Understand Firebird L5 return sensor fault codes with clear causes, checks and parts advice from Boiler Spares. Diagnose the issue now.
- [Firebird L6 - Flow Sensor Fault](https://boilerandspares.co.uk/fault-codes/firebird-l6/) - See what the Firebird L6 flow sensor fault means, common causes and the parts often needed to fix it. Check the fault details and next steps.
- [Firebird L7 - Pump Fault](https://boilerandspares.co.uk/fault-codes/firebird-l7/) - See what the Firebird L7 pump fault code means, common causes, and practical fixes from boiler parts specialists. Check the fault guidance.
- [Firebird L8 - Fan Fault](https://boilerandspares.co.uk/fault-codes/firebird-l8/) - See what the Firebird L8 fan fault code means, common causes and the parts you may need to fix it. Check the fault code guide now.
- [Firebird L9 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/firebird-l9/) - Fix the Firebird L9 condensate blocked fault code with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Firebird L10 - PCB Fault](https://boilerandspares.co.uk/fault-codes/firebird-l10/) - Fix Firebird L10 PCB boiler fault codes with clear diagnosis advice and compatible spare parts. Identify the right fix and order parts.
- [Warmflow E1 - Ignition Lockout](https://boilerandspares.co.uk/fault-codes/warmflow-e1/) - See what the Warmflow E1 ignition lockout fault code means, likely causes and parts to check, then identify the right boiler spares.
- [Warmflow E2 - Flame Failure](https://boilerandspares.co.uk/fault-codes/warmflow-e2/) - Fix Warmflow E2 flame failure faults with clear fault code guidance, likely causes and spare parts options. Check symptoms and order parts.
- [Warmflow E3 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/warmflow-e3/) - Fix a Warmflow E3 overheat lockout fault with clear fault code guidance, likely causes and parts help. Check symptoms and order spares.
- [Warmflow E4 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/warmflow-e4/) - Fix Warmflow E4 low water pressure faults with clear causes, part checks and repair guidance. Identify the issue fast and order spares.
- [Warmflow E5 - Flow Sensor Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e5/) - Understand the Warmflow E5 flow sensor fault, its common causes and likely fixes, with clear guidance on parts and next steps to repair it.
- [Warmflow E6 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e6/) - Fix a Warmflow E6 return sensor fault with clear checks, likely causes and parts advice from Boiler Spares. Diagnose the issue now.
- [Warmflow E7 - Pump Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e7/) - Understand Warmflow E7 pump faults, likely causes and practical fixes, with clear guidance to help identify the issue and order the right part.
- [Warmflow E8 - PCB Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e8/) - See what the Warmflow E8 PCB fault code means, common causes and likely fixes, with clear boiler fault guidance. Check the fault details.
- [Firebird L11 - APS Fault](https://boilerandspares.co.uk/fault-codes/firebird-l11/) - Understand the Firebird L11 fault code, its likely causes and practical checks to help identify the issue. See the full guide.
- [Firebird L12 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/firebird-l12/) - Understand the Firebird L12 DHW sensor fault code, what causes it and the parts you may need, then check the fault code guide.
- [Firebird L13 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/firebird-l13/) - Fix a Firebird L13 diverter valve fault code with clear causes, checks and parts guidance. Identify the issue fast and order the right spares.
- [Firebird L14 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/firebird-l14/) - Understand the Firebird L14 gas valve fault code, common causes and fix steps. Diagnose the issue faster with Boiler Spares guidance.
- [Firebird L15 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/firebird-l15/) - Understand Firebird L15 combustion fault causes, checks and fixes with clear guidance. Identify the issue fast and order the right part.
- [Firebird L16 - PCB Communication Error](https://boilerandspares.co.uk/fault-codes/firebird-l16/) - Fix Firebird L16 PCB communication errors with clear fault code guidance, likely causes and parts advice. Identify the issue and order spares.
- [Firebird L17 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/firebird-l17/) - Fix the Firebird L17 pressure sensor fault with clear code guidance, likely causes and parts advice. Check the fault and order spares.
- [Firebird L18 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/firebird-l18/) - Firebird L18 rapid temperature rise fault code explained with likely causes and practical checks to narrow the issue. See the next steps.
- [Firebird L19 - Frost Protection](https://boilerandspares.co.uk/fault-codes/firebird-l19/) - Get the Firebird L19 frost protection fault code explained with likely causes and checks, so you can identify the issue and order the right part.
- [Firebird L20 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/firebird-l20/) - Firebird L20 eBUS fault code explained with likely causes and compatible Boiler Spares parts to speed repairs. Check the code and order parts.
- [Warmflow E9 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e9/) - Fix Warmflow E9 DHW sensor faults with clear diagnosis, compatible Boiler Spares parts and fitting guidance. Check the code and order the right part.
- [Warmflow E10 - Fan Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e10/) - Fix a Warmflow E10 fan fault with Boiler Spares guidance, clear checks and matched parts. Identify the issue fast and order the right spares.
- [Warmflow E11 - APS Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e11/) - Understand Warmflow E11 APS fault codes with clear causes, checks and parts guidance from Boiler Spares. Diagnose the issue fast.
- [Warmflow E12 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/warmflow-e12/) - Fix Warmflow E12 condensate blocked faults with clear code guidance, likely causes and parts advice. Check symptoms and order spares.
- [Warmflow E13 - Diverter Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e13/) - Understand Warmflow E13 diverter fault codes with clear causes, checks and parts guidance from Boiler Spares. Diagnose the issue fast.
- [Warmflow E14 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e14/) - Troubleshoot Warmflow E14 gas valve faults with clear checks, likely causes and spare part guidance from Boiler Spares. Fix the issue fast.
- [Warmflow E15 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e15/) - Understand the Warmflow E15 combustion fault, common causes and likely fixes with clear guidance. Check symptoms and next steps.
- [Warmflow E16 - PCB Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e16/) - Get the right Warmflow E16 PCB fault boiler spares fast, with compatible parts and clear listings. Check stock and order the correct part.
- [Warmflow E17 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/warmflow-e17/) - Understand Warmflow E17 pressure sensor fault code, common causes and likely fixes so you can diagnose issues faster. See the fault guide.
- [Warmflow E18 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/warmflow-e18/) - Fix Warmflow E18 rapid temperature rise faults with clear causes, checks and parts guidance from Boiler Spares. Identify the right fix.
- [Warmflow E19 - Frost Protection](https://boilerandspares.co.uk/fault-codes/warmflow-e19/) - Fix a Warmflow E19 frost protection fault code with clear checks, likely causes and boiler spares guidance. See the fault steps now.
- [Warmflow E20 - Outdoor Sensor](https://boilerandspares.co.uk/fault-codes/warmflow-e20/) - Fix Warmflow E20 outdoor sensor faults with clear code guidance, likely causes and compatible boiler spares. Check the remedy steps.
- [Remeha 01 - No Flame Detected](https://boilerandspares.co.uk/fault-codes/remeha-01/) - Fix a Remeha 01 fault code with clear no-flame-detected checks, likely causes and parts guidance. Identify the fault and order spares.
- [Remeha 02 - Safety Thermostat Activated](https://boilerandspares.co.uk/fault-codes/remeha-02/) - Fix the Remeha 02 safety thermostat activated fault with clear causes, checks and parts guidance from Boiler Spares. View the code.
- [Remeha 03 - Flue Gas Thermostat Activated](https://boilerandspares.co.uk/fault-codes/remeha-03/) - Understand Remeha 03 flue gas thermostat activated fault codes, common causes and fixes, with clear parts guidance. Check the fault now.
- [Remeha 04 - False Flame Signal](https://boilerandspares.co.uk/fault-codes/remeha-04/) - Understand Remeha 04 false flame signal fault code, its likely causes and the parts to check. Identify the fault fast and view spares.
- [Remeha 05 - Flame Lost During Operation](https://boilerandspares.co.uk/fault-codes/remeha-05/) - Fix a Remeha 05 flame lost during operation fault with clear causes, checks and parts guidance from Boiler Spares. View the fault code.
- [Remeha 06 - Fan Fault](https://boilerandspares.co.uk/fault-codes/remeha-06/) - Understand the Remeha 06 fan fault, common causes and repair options, with clear guidance to help diagnose the issue. See the fix.
- [Remeha 07 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/remeha-07/) - Fix a Remeha 07 air pressure switch fault with clear code advice, likely causes and spare parts support. Check symptoms and order parts.
- [Remeha 08 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/remeha-08/) - Understand the Remeha 08 gas valve fault, common causes and fixes, with clear guidance to diagnose the issue and order the right spare part.
- [Remeha 10 - Flow Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/remeha-10/) - Fix Remeha 10 flow temperature sensor faults with clear checks, likely causes and parts guidance. Identify the issue fast and order spares.
- [Remeha 11 - Return Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/remeha-11/) - Fix a Remeha 11 return temperature sensor fault with clear fault code guidance, likely causes and parts help. Identify the issue fast.
- [Remeha 12 - DHW Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/remeha-12/) - See what the Remeha 12 DHW temperature sensor fault code means, common causes and likely fixes, then identify the right spare part.
- [Remeha 14 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/remeha-14/) - Fix the Remeha 14 low water pressure fault with clear causes, practical checks and spares guidance. Identify the issue and act.
- [Remeha 15 - Pump Fault](https://boilerandspares.co.uk/fault-codes/remeha-15/) - Understand the Remeha 15 pump fault code, its common causes and fixes, with clear boiler fault guidance. Check the fault details now.
- [Remeha 16 - Pump Over-Speed](https://boilerandspares.co.uk/fault-codes/remeha-16/) - Fix a Remeha 16 pump over-speed fault with clear causes, checks and part guidance from Boiler Spares. See the fault details and order spares.
- [Remeha 18 - PCB Fault](https://boilerandspares.co.uk/fault-codes/remeha-18/) - Get clear fixes for the Remeha 18 PCB fault code with boiler spares advice and fault checks. Identify the issue fast and see your next step.
- [Remeha 20 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/remeha-20/) - Understand the Remeha 20 outdoor sensor fault, what causes it and how to fix it with clear steps. Check symptoms and order the right part.
- [Remeha 24 - Condensate Drain Blocked](https://boilerandspares.co.uk/fault-codes/remeha-24/) - Fix the Remeha 24 condensate drain blocked fault code with clear checks, likely causes and parts advice from Boiler Spares. See the guide.
- [Remeha 27 - Ignition Electrode Fault](https://boilerandspares.co.uk/fault-codes/remeha-27/) - Fix the Remeha 27 ignition electrode fault with clear fault-code guidance, likely causes and part advice. Identify the issue and order spares.
- [Remeha 30 - Three-Way Valve Fault](https://boilerandspares.co.uk/fault-codes/remeha-30/) - Fix Remeha 30 three-way valve fault codes with clear checks, likely causes and spare part guidance. Identify the issue fast, then view the guide.
- [Remeha 35 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/remeha-35/) - Understand the Remeha 35 combustion fault, common causes and the parts to check, with clear guidance to diagnose the issue and order spares.
- [Hamworthy E01 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/hamworthy-e01/) - Fix Hamworthy E01 ignition failure faults with clear causes, part guidance and repair steps from Boiler Spares. Identify the issue fast.
- [Hamworthy E02 - Flame Loss](https://boilerandspares.co.uk/fault-codes/hamworthy-e02/) - Fix Hamworthy E02 flame loss faults with clear checks, likely causes and parts guidance. Identify the issue faster and order spares.
- [Hamworthy E03 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/hamworthy-e03/) - Understand the Hamworthy E03 overheat protection fault code, its common causes and likely fixes, then identify the right boiler spares.
- [Hamworthy E04 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/hamworthy-e04/) - Fix the Hamworthy E04 low water pressure fault with clear code guidance, likely causes and spare parts support. Check the fault now.
- [Hamworthy E05 - Fan Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e05/) - Understand the Hamworthy E05 fan fault code, common causes and checks, with clear boiler spares guidance. Diagnose the issue now.
- [Hamworthy E06 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e06/) - Fix a Hamworthy E06 air pressure switch fault with clear causes, checks and parts advice from Boiler Spares. Identify the issue fast.
- [Hamworthy E07 - Flow Sensor Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e07/) - Understand the Hamworthy E07 flow sensor fault, common causes and practical fixes with spares guidance. Check symptoms and next steps.
- [Hamworthy E08 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e08/) - Understand the Hamworthy E08 return sensor fault, its likely causes and fix options. Check the code meaning and order the right spare.
- [Hamworthy E10 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e10/) - Understand the Hamworthy E10 gas valve fault, common causes and repair options with expert guidance. Check the fault details now.
- [Hamworthy E11 - PCB Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e11/) - Buy genuine Hamworthy E11 PCB fault boiler spares with fast UK delivery and accurate part matching. Check compatible parts and order online.
- [Hamworthy E12 - Pump Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e12/) - Understand the Hamworthy E12 pump fault code, common causes and fixes, with clear boiler spares guidance. Check the fault and order parts.
- [Hamworthy E15 - Flue Temperature Limit](https://boilerandspares.co.uk/fault-codes/hamworthy-e15/) - Understand Hamworthy E15 flue temperature limit fault code fast with clear causes, checks and parts guidance. Identify the fault and fix it.
- [Hamworthy E20 - Condensate Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e20/) - Understand the Hamworthy E20 condensate fault, common causes and checks, with clear guidance to identify the issue and order the right part.
- [Firebird L1 - Ignition Lockout](https://boilerandspares.co.uk/fault-codes/firebird-l1/) - Understand Firebird L1 ignition lockout fault codes, likely causes and practical fixes from Boiler Spares. Check symptoms and next steps.
- [Remeha 22 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/remeha-22/) - Get clear fixes for the Remeha 22 overheat protection fault code, with likely causes and parts guidance. Check the fault and order spares.
- [Remeha 23 - Flow/Return Differential Too Large](https://boilerandspares.co.uk/fault-codes/remeha-23/) - Fix Remeha 23 fault code flow/return differential too large with clear checks, likely causes and parts guidance. See the fault steps.
- [Remeha 25 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/remeha-25/) - Fix a Remeha 25 rapid temperature rise fault with clear code checks, likely causes and parts guidance. See the fault steps now.
- [Remeha 26 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/remeha-26/) - Get the fix for the Remeha 26 Flame Detected After Shutdown fault code, with clear causes, checks and parts advice. Diagnose the issue.
- [Remeha 28 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/remeha-28/) - Fix Remeha 28 combustion faults with clear code meanings, likely causes and parts advice. Identify the issue fast and check the next fix.
- [Remeha 29 - Diverter Valve Timeout](https://boilerandspares.co.uk/fault-codes/remeha-29/) - Fix a Remeha 29 diverter valve timeout fault with clear fault code guidance, likely causes and parts help. Check the steps and order spares.
- [Remeha 31 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/remeha-31/) - Understand Remeha 31 eBUS fault codes fast with clear causes, checks and fixes for your boiler. See the fault guide and next steps.
- [Remeha 32 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/remeha-32/) - Fix a Remeha 32 mains voltage fault with a clear code explanation, likely causes and practical checks. See the fault details and next steps.
- [Remeha 33 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/remeha-33/) - Understand the Remeha 33 EEPROM error, common causes and the parts you may need from Boiler Spares. Check the fault and order the fix.
- [Remeha 34 - Phase/Neutral Reversed](https://boilerandspares.co.uk/fault-codes/remeha-34/) - Fix a Remeha 34 phase/neutral reversed fault with clear causes, checks and parts guidance from Boiler Spares. Identify the issue now.
- [Remeha 36 - Coding Plug Fault](https://boilerandspares.co.uk/fault-codes/remeha-36/) - Fix a Remeha 36 coding plug fault with clear fault code guidance, likely causes and compatible spare parts. Check the right fix.
- [Remeha 37 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/remeha-37/) - Fix the Remeha 37 Flue Gas Overheat fault with clear causes, checks and parts guidance from Boiler Spares. See the code details.
- [Remeha 38 - Frost Protection](https://boilerandspares.co.uk/fault-codes/remeha-38/) - Fix a Remeha 38 frost protection fault with clear fault-code checks, likely causes and spare part guidance. See the steps now.
- [Remeha 39 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/remeha-39/) - Get a clear explanation of the Remeha 39 pressure sensor fault, common causes and fixes, with boiler spares guidance. Check the code now.
- [Remeha 40 - Pump Speed Error](https://boilerandspares.co.uk/fault-codes/remeha-40/) - Understand the Remeha 40 pump speed error, its likely causes and fixes. Use our clear guide to diagnose the fault and order parts.
- [Hamworthy E13 - Condensate Trap Full](https://boilerandspares.co.uk/fault-codes/hamworthy-e13/) - Fix Hamworthy E13 condensate trap faults with clear code guidance, likely causes and spare parts support. Check symptoms and order parts.
- [Hamworthy E14 - Communication Error](https://boilerandspares.co.uk/fault-codes/hamworthy-e14/) - Fix Hamworthy E14 communication error boiler faults with clear code guidance, likely causes and parts advice. Check the fault and order spares.
- [Hamworthy E16 - Gas Pressure Too Low](https://boilerandspares.co.uk/fault-codes/hamworthy-e16/) - Fix the Hamworthy E16 gas pressure too low fault code with clear checks, likely causes and parts guidance. See the fault and next steps.
- [Hamworthy E17 - Overheat Return](https://boilerandspares.co.uk/fault-codes/hamworthy-e17/) - Fix Hamworthy E17 overheat return fault codes with clear causes, checks and parts guidance. Identify the fault fast and view the next step.
- [Hamworthy E18 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/hamworthy-e18/) - Fix a Hamworthy E18 rapid temperature rise fault with clear causes, checks and parts guidance. Identify the issue fast and see what to replace.
- [Hamworthy E19 - Diverter Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e19/) - Understand the Hamworthy E19 diverter fault with clear causes, checks and parts guidance from Boiler Spares. See the fix and order parts.
- [Hamworthy E21 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/hamworthy-e21/) - Fix Hamworthy E21 fault code on eBUS boilers with clear fault checks, likely causes and parts guidance. See the troubleshooting steps.
- [Hamworthy E22 - Outdoor Sensor](https://boilerandspares.co.uk/fault-codes/hamworthy-e22/) - Get the meaning of Hamworthy E22 outdoor sensor fault code, common causes and the right replacement parts. Check the code and order spares.
- [Hamworthy E23 - Frost Protection](https://boilerandspares.co.uk/fault-codes/hamworthy-e23/) - See what the Hamworthy E23 frost protection fault code means, common causes and the right spare parts to fix it. Check the code now.
- [Hamworthy E24 - Combustion Error](https://boilerandspares.co.uk/fault-codes/hamworthy-e24/) - Buy Hamworthy E24 combustion error spare parts from Boiler Spares. Match the fault code fast and order the right part online today.
- [Hamworthy E25 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/hamworthy-e25/) - Fix the Hamworthy E25 EEPROM error fault code with clear fault checks, likely causes and parts guidance. See the repair steps.
- [Johnson & Starley 37 - Low Water Pressure (Numeric Display)](https://boilerandspares.co.uk/fault-codes/johnson-starley-37/) - Fix Johnson & Starley fault code 37 for low water pressure with clear checks, likely causes and parts help. Use the guide now.
- [ATAG 133 - Ignition Failure — No Flame After 5 Attempts](https://boilerandspares.co.uk/fault-codes/atag-133/) - Fix ATAG 133 ignition failure with clear checks for no flame after 5 attempts, plus likely causes and parts guidance. Diagnose the fault.
- [ATAG 110 - Safety Temperature Exceeded / Overheat](https://boilerandspares.co.uk/fault-codes/atag-110/) - Fix the ATAG 110 safety temperature exceeded overheat fault code with clear causes, checks and parts guidance. Diagnose the issue now.
- [ATAG 20 - Flow Sensor Error](https://boilerandspares.co.uk/fault-codes/atag-20/) - Understand the ATAG 20 flow sensor error, its likely causes and fixes, with clear fault code guidance. Check symptoms and next steps.
- [ATAG 40 - Return Sensor Error](https://boilerandspares.co.uk/fault-codes/atag-40/) - Understand ATAG 40 return sensor error codes fast with clear fault causes, checks and parts guidance. Identify the issue and fix it.
- [ATAG 78 - Water Pressure Out of Range](https://boilerandspares.co.uk/fault-codes/atag-78/) - Fix ATAG 78 water pressure out of range faults with clear checks, likely causes and parts guidance. See the steps and order spares.
- [ATAG 108 - Low Water Pressure — Refill Required](https://boilerandspares.co.uk/fault-codes/atag-108/) - Fix ATAG 108 low water pressure refill faults with clear guidance, likely causes and spare parts support. Check the steps and order parts.
- [ATAG 129 - Fan Not Starting](https://boilerandspares.co.uk/fault-codes/atag-129/) - Fix an ATAG 129 fan not starting fault code with clear checks, likely causes and spare parts guidance. Identify the issue and order the part.
- [ATAG 151 - Fan Speed Error / Control Unit Fault](https://boilerandspares.co.uk/fault-codes/atag-151/) - Fix ATAG 151 fan speed error with clear fault checks, control unit guidance and spare part support. See the likely cause and next steps.
- [ATAG 154 - Return Temperature Higher Than Flow / Rapid Rise](https://boilerandspares.co.uk/fault-codes/atag-154/) - Fix ATAG 154 return temperature higher than flow with fault code guidance from Boiler Spares. Check likely causes and next repair steps.
- [ATAG 303 - PCB Error](https://boilerandspares.co.uk/fault-codes/atag-303/) - Fix ATAG 303 PCB error fast with Boiler Spares fault code guidance. Identify likely causes and next checks before you order parts.
- [ATAG 304 - Too Many Resets](https://boilerandspares.co.uk/fault-codes/atag-304/) - Fix the ATAG 304 fault code with clear reset checks, likely causes and spare part guidance. Identify the fault fast and order parts.
- [ATAG 501 - No Flame Detected](https://boilerandspares.co.uk/fault-codes/atag-501/) - Fix ATAG 501 no flame detected faults with clear code guidance, likely causes and spare part help from Boiler Spares. View the fix steps.
- [ATAG 61 - Bus Communication Error](https://boilerandspares.co.uk/fault-codes/atag-61/) - Understand ATAG 61 bus communication error code, common causes and practical fixes for faster fault diagnosis. See the troubleshooting steps.
- [ATAG 111 - Pressure Too High](https://boilerandspares.co.uk/fault-codes/atag-111/) - Fix the ATAG 111 pressure too high fault code with clear causes, checks and repair advice. Identify the fault fast and book the right part.
- [Johnson & Starley E04 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e04/) - Fix Johnson & Starley E04 Return NTC faults with clear causes, checks and part guidance from Boiler Spares. See the fault code steps.
- [Johnson & Starley E06 - Fan Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e06/) - Fix a Johnson & Starley E06 fan fault with clear fault code guidance and compatible boiler spares. Check symptoms and order the right part.
- [Johnson & Starley E07 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e07/) - Fix Johnson & Starley E07 gas valve faults with clear code guidance, likely causes and parts support from Boiler Spares. Check the steps now.
- [Johnson & Starley E10 - Overheat](https://boilerandspares.co.uk/fault-codes/johnson-starley-e10/) - Fix Johnson & Starley E10 overheat fault code with clear causes, checks and parts guidance from Boiler Spares. See the fault steps now.
- [Johnson & Starley E11 - PCB Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e11/) - See what the Johnson & Starley E11 PCB fault code means, common causes and fix checks, then order the right boiler spares online.
- [Johnson & Starley E13 - Low Pressure](https://boilerandspares.co.uk/fault-codes/johnson-starley-e13/) - Fix Johnson & Starley E13 low pressure faults with clear code meaning, likely causes and practical checks. See the fault code guide.
- [Johnson & Starley E14 - Pump Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e14/) - Fix Johnson & Starley E14 pump fault codes fast with clear causes, checks and repair guidance. Identify the issue and order the right part.
- [Johnson & Starley E15 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/johnson-starley-e15/) - Fix Johnson & Starley E15 condensate blocked faults with clear causes, repair steps and parts guidance. Check the code and order spares.
- [Johnson & Starley E16 - DHW NTC Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e16/) - See what the Johnson & Starley E16 DHW NTC fault code means, common causes and fixes, with clear fault-finding steps. Check the code.
- [Johnson & Starley E17 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e17/) - Fix a Johnson & Starley E17 diverter valve fault with clear fault code guidance, likely causes and parts advice. Check the solution.
- [Johnson & Starley E18 - APS Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e18/) - Fix Johnson & Starley E18 APS fault code with clear fault checks, likely causes and parts guidance. Identify the issue and order spares.
- [Johnson & Starley E19 - Flame Instability](https://boilerandspares.co.uk/fault-codes/johnson-starley-e19/) - Fix the Johnson & Starley E19 flame instability code with clear fault checks, likely causes and parts guidance. See the next steps.
- [Johnson & Starley E20 - Flame Lost](https://boilerandspares.co.uk/fault-codes/johnson-starley-e20/) - Fix the Johnson & Starley E20 flame lost fault with clear causes, checks and parts guidance from Boiler Spares. See the code details now.
- [Johnson & Starley E21 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/johnson-starley-e21/) - Fix Johnson & Starley E21 rapid temperature rise faults with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Johnson & Starley E22 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e22/) - Fix the Johnson & Starley E22 combustion fault with clear causes, checks and parts guidance from Boiler Spares. Identify the next step.
- [Johnson & Starley E23 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e23/) - Fix Johnson & Starley E23 pressure sensor faults with clear causes, checks and parts advice from Boiler Spares. Identify the issue fast.
- [Johnson & Starley E24 - Frost Protection](https://boilerandspares.co.uk/fault-codes/johnson-starley-e24/) - Fix Johnson & Starley E24 frost protection fault codes with clear checks, likely causes and spare part guidance. View the fault code page.
- [Johnson & Starley 2 - Flame Failure](https://boilerandspares.co.uk/fault-codes/johnson-starley-2/) - Fix the Johnson & Starley 2 flame failure fault code with clear fault causes, part checks and repair advice. See the steps now.
- [Johnson & Starley 4 - APS Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-4/) - Understand Johnson & Starley 4 - APS fault code fast, with clear causes and practical checks. Identify the issue and order the right spare part.
- [Johnson & Starley 5 - Overheat](https://boilerandspares.co.uk/fault-codes/johnson-starley-5/) - Get clear causes, checks and parts guidance for the Johnson & Starley 5 overheat fault code so you can fix the issue sooner. See the fault guide.
- [ATAG 10 - Flow NTC Fault](https://boilerandspares.co.uk/fault-codes/atag-10/) - Identify ATAG 10 Flow NTC fault codes, common causes and likely fixes for boilers. Use the guide to diagnose the issue and order parts.
- [ATAG 11 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/atag-11/) - Identify the ATAG 11 Return NTC fault and source the right boiler spares fast with clear fault code guidance. Check the part you need.
- [ATAG 12 - DHW NTC Fault](https://boilerandspares.co.uk/fault-codes/atag-12/) - Understand the ATAG 12 DHW NTC fault, what causes it, and the parts often needed to fix it. Check symptoms and order the right spares.
- [ATAG 15 - Fan Fault](https://boilerandspares.co.uk/fault-codes/atag-15/) - Understand ATAG 15 fan fault codes fast with clear causes, likely fixes and parts guidance. Diagnose the issue and check the right spares.
- [ATAG 16 - APS Fault](https://boilerandspares.co.uk/fault-codes/atag-16/) - Understand ATAG 16 APS fault codes fast with clear causes, practical checks and parts guidance from Boiler Spares. Fix the issue with confidence.
- [ATAG 17 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/atag-17/) - Understand ATAG 17 gas valve fault codes, what causes them and how to fix them. Get clear fault guidance and order the right spare part.
- [ATAG 18 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/atag-18/) - Fix ATAG 18 ignition failure faults with clear code checks, likely causes and spare part guidance. Use the guide to diagnose the issue.
- [ATAG 19 - Flame Lost](https://boilerandspares.co.uk/fault-codes/atag-19/) - Fix ATAG 19 flame lost fault code with clear checks, likely causes and spare part guidance from Boiler Spares. See the fault details now.
- [ATAG 21 - Overheat](https://boilerandspares.co.uk/fault-codes/atag-21/) - Fix ATAG 21 overheat fault code with clear checks, likely causes and Boiler Spares parts support. See the fault steps and order the right part.
- [ATAG 22 - Low Pressure](https://boilerandspares.co.uk/fault-codes/atag-22/) - ATAG 22 low pressure fault code explained by Boiler Spares, with clear causes and repair guidance to help fix boiler pressure issues. Check now.
- [ATAG 23 - Pump Fault](https://boilerandspares.co.uk/fault-codes/atag-23/) - Understand ATAG 23 pump fault codes fast with clear causes, checks and fixes from Boiler Spares. Identify the fault and order the right part.
- [ATAG 24 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/atag-24/) - Fix the ATAG 24 rapid temperature rise fault code with likely causes, repair steps and parts advice. Check the fault and order spares.
- [ATAG 25 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/atag-25/) - Fix ATAG 25 condensate blocked faults with clear cause checks, likely parts and repair guidance. Identify the issue and order spares.
- [ATAG 26 - Diverter Fault](https://boilerandspares.co.uk/fault-codes/atag-26/) - Understand ATAG fault code 26 and diverter valve issues fast, with clear causes and fixes. Check symptoms and order the right part.
- [ATAG 27 - PCB Fault](https://boilerandspares.co.uk/fault-codes/atag-27/) - Find ATAG 27 PCB fault details and matching boiler spares fast, with clear part information to help you identify the right replacement.
- [ATAG 28 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/atag-28/) - Understand ATAG 28 combustion fault codes with clear causes, checks and fix options. Diagnose the issue faster and see what to do next.
- [ATAG 29 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/atag-29/) - Fix ATAG 29 pressure sensor fault codes with clear causes, checks and spare part guidance from Boiler Spares. See the fault code steps.
- [ATAG 30 - Frost Protection](https://boilerandspares.co.uk/fault-codes/atag-30/) - See what ATAG 30 frost protection fault code means, common causes, and practical checks to fix it fast. Use our fault guide now.
- [ATAG 31 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/atag-31/) - Understand ATAG 31 eBUS fault codes fast with clear causes, checks and parts guidance from Boiler Spares. See the fix and next steps.
- [ATAG 32 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/atag-32/) - ATAG 32 fault code means flue gas overheat. See likely causes, checks and boiler spares guidance to diagnose the issue and fix it safely.
- [ATAG 33 - Outdoor Sensor](https://boilerandspares.co.uk/fault-codes/atag-33/) - ATAG 33 outdoor sensor fault code explained with likely causes and matching boiler spares. Check the fault and order the right part.
- [ATAG 34 - Mains Voltage](https://boilerandspares.co.uk/fault-codes/atag-34/) - Understand ATAG 34 mains voltage fault codes fast with clear causes, checks and parts advice. Identify the issue and order the right spare.
- [ATAG 35 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/atag-35/) - Fix ATAG 35 EEPROM boiler errors with clear fault code guidance and parts advice from Boiler Spares. Identify the issue and order the right part.
- [ATAG 36 - Flame After Shutdown](https://boilerandspares.co.uk/fault-codes/atag-36/) - See what causes ATAG 36 flame after shutdown, the checks to make, and matching spare parts to fix the fault. View the fault guide.
- [Grant EE1 - High Pressure / Pump Failure / Airlock](https://boilerandspares.co.uk/fault-codes/grant-ee1/) - Fix Grant EE1 fault codes caused by high pressure or airlocks with clear checks, likely causes and parts advice. Identify the fault and order spares.
- [Grant EE2 - Low Pressure](https://boilerandspares.co.uk/fault-codes/grant-ee2/) - Understand Grant EE2 low pressure fault codes fast with clear causes, likely fixes and parts guidance. Check the fault and order spares.
- [Grant PP1 - Flow/Return Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/grant-pp1/) - See what the Grant PP1 flow/return temperature sensor fault means, likely causes and fixes, then check the right Boiler Spares parts.
- [Grant BURNER LOCKOUT - Burner Lockout](https://boilerandspares.co.uk/fault-codes/grant-burner-lockout/) - Understand Grant BURNER LOCKOUT fault codes with clear causes, checks and fix advice from Boiler Spares. Identify the issue fast.
- [Grant NO FUEL - No Oil Supply / Empty Tank](https://boilerandspares.co.uk/fault-codes/grant-no-fuel/) - Get clear steps to diagnose Grant NO FUEL faults caused by no oil supply or an empty tank, with practical checks and parts guidance. Fix it fast.
- [Grant OVERHEAT - Overheat Thermostat Activated](https://boilerandspares.co.uk/fault-codes/grant-overheat/) - Fix a Grant OVERHEAT fault fast with clear causes, checks and thermostat reset guidance for Grant boilers. See the fault code steps.
- [Grant SMOKE/FLUE FAULT - Visible Smoke or High Smoke Number](https://boilerandspares.co.uk/fault-codes/grant-smoke-flue-fault/) - Fix Grant SMOKE/FLUE FAULT with clear checks for visible or heavy smoke, plus likely causes and parts guidance. See the fault steps.
- [Grant E01 - Internal Control Fault](https://boilerandspares.co.uk/fault-codes/grant-e01/) - Identify Grant E01 internal control fault causes, checks and likely fixes with clear boiler-specific guidance. See the fault code steps.
- [Grant RED LIGHT STEADY - UV Sensor / Gas Valve Fault (Vortex Blue)](https://boilerandspares.co.uk/fault-codes/grant-red-light-steady/) - Fix the Grant red light steady UV sensor or gas valve fault with clear fault code guidance and parts support. Check symptoms and order spares.
- [Johnson & Starley E01 - Ignition Lockout](https://boilerandspares.co.uk/fault-codes/johnson-starley-e01/) - Fix a Johnson & Starley E01 ignition lockout with clear fault code guidance and parts support from Boiler Spares. Check the fix.
- [Johnson & Starley E02 - False Flame Lockout](https://boilerandspares.co.uk/fault-codes/johnson-starley-e02/) - Fix Johnson & Starley E02 false flame lockout with fault code advice, likely causes and parts support. Check the fault and order spares.
- [Johnson & Starley E03 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/johnson-starley-e03/) - Fix a Johnson & Starley E03 overheat lockout fault with clear checks, likely causes and parts guidance. See the fault code steps.
- [Johnson & Starley E05 - Fan Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e05/) - See what the Johnson & Starley E05 fan fault code means, common causes and practical checks, then order the right Boiler Spares part.
- [Johnson & Starley E08 - Flame Circuit Failure](https://boilerandspares.co.uk/fault-codes/johnson-starley-e08/) - Fix Johnson & Starley E08 flame circuit failures with clear fault code guidance, likely causes and parts advice. Check the next steps.
- [Johnson & Starley E09 - Gas Valve Feedback Error](https://boilerandspares.co.uk/fault-codes/johnson-starley-e09/) - Fix Johnson & Starley E09 gas valve feedback errors with clear fault code guidance, likely causes and parts help. Check the steps now.
- [Johnson & Starley E12 - EEPROM Lockout](https://boilerandspares.co.uk/fault-codes/johnson-starley-e12/) - Identify the Johnson & Starley E12 EEPROM lockout fault code, what it means and likely fixes, then check the right boiler spares.
- [Johnson & Starley E33 - Return Thermistor Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e33/) - Fix Johnson & Starley E33 return thermistor faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Johnson & Starley E35 - Flow Thermistor Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-e35/) - Fix a Johnson & Starley E35 flow thermistor fault with clear causes, checks and parts guidance from Boiler Spares. See the repair steps.
- [Johnson & Starley F37 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/johnson-starley-f37/) - Fix the Johnson & Starley F37 low water pressure fault with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Johnson & Starley F40 - Water Pressure Too High](https://boilerandspares.co.uk/fault-codes/johnson-starley-f40/) - See why your Johnson & Starley F40 shows water pressure too high, with clear fault advice and parts support. Check the fix now.
- [Johnson & Starley F52 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/johnson-starley-f52/) - Fix a Johnson & Starley F52 DHW sensor fault with clear fault code guidance, likely causes and parts help. Diagnose the issue and order spares.
- [Johnson & Starley F53 - Flue Temperature Sensor Lockout](https://boilerandspares.co.uk/fault-codes/johnson-starley-f53/) - Fix Johnson & Starley F53 flue temperature sensor lockout with clear fault code guidance and compatible Boiler Spares parts. Order the right part.
- [Johnson & Starley 1 - Ignition Failure (Numeric Display)](https://boilerandspares.co.uk/fault-codes/johnson-starley-1/) - Fix Johnson & Starley 1 Ignition Failure with clear fault code advice, likely causes and parts guidance. Check symptoms and next steps.
- [Johnson & Starley 3 - Overheat (Numeric Display)](https://boilerandspares.co.uk/fault-codes/johnson-starley-3/) - Fix Johnson & Starley 3 overheat fault code fast with clear causes, checks and parts guidance. See the fault details and identify the next fix.
- [Grant EE3 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/grant-ee3/) - See what Grant EE3 means, what causes the overheat protection fault, and how to check likely issues before you call an engineer.
- [Grant EE4 - Flow Sensor Fault](https://boilerandspares.co.uk/fault-codes/grant-ee4/) - Fix Grant EE4 flow sensor faults with clear checks, common causes and parts advice from Boiler Spares. Identify the issue and order spares.
- [Grant EE5 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/grant-ee5/) - Fix a Grant EE5 return sensor fault with clear checks, likely causes and parts guidance from Boiler Spares. View the guide and identify the fix.
- [Grant PP2 - Pump Fault](https://boilerandspares.co.uk/fault-codes/grant-pp2/) - Clear guide to Grant PP2 pump faults, with likely causes, part checks and fixes to help identify the issue. See the fault steps.
- [Grant PP3 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/grant-pp3/) - Fix a Grant PP3 low water pressure fault with clear causes, checks and parts guidance from Boiler Spares. See the next steps.
- [Grant E02 - Flame Failure](https://boilerandspares.co.uk/fault-codes/grant-e02/) - Fix Grant E02 flame failure faults with clear checks, common causes and parts advice. Save time on diagnosis and view the guide.
- [Grant E03 - Fan Fault](https://boilerandspares.co.uk/fault-codes/grant-e03/) - See what the Grant E03 fan fault code means, common causes and practical checks to help diagnose the issue. View the guide and next steps.
- [Grant E04 - PCB Fault](https://boilerandspares.co.uk/fault-codes/grant-e04/) - Fix Grant E04 PCB fault codes with clear causes, tested checks and parts guidance from Boiler Spares. Identify the fault and order the right fix.
- [Grant E05 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/grant-e05/) - Fix Grant E05 condensate blocked fault code with clear fault checks, likely causes and parts guidance. Identify the issue and order spares.
- [Grant E06 - Air Pressure Switch](https://boilerandspares.co.uk/fault-codes/grant-e06/) - Fix Grant E06 air pressure switch faults with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order the right spares.
- [Grant E07 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/grant-e07/) - Understand Grant E07 flue gas overheat faults, common causes and the parts that may need replacing. Check symptoms and order spares.
- [Grant E08 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/grant-e08/) - Identify the Grant E08 DHW sensor fault, match the right boiler spares fast, and check the next part to order online.
- [Grant E09 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/grant-e09/) - Understand Grant E09 diverter valve fault codes with clear causes, checks and parts advice from Boiler Spares. Diagnose the issue now.
- [Grant E10 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/grant-e10/) - Fix a Grant E10 combustion fault with clear checks, likely causes and parts advice. Identify the issue fast and view suitable spares.
- [Heatline F28 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/heatline-f28/) - Understand Heatline F28 ignition failure causes, fixes and likely parts needed with clear fault code guidance. Check the next steps.
- [Heatline F29 - Flame Loss During Operation](https://boilerandspares.co.uk/fault-codes/heatline-f29/) - Fix Heatline F29 flame loss during operation with clear fault checks, likely causes and parts guidance. See the repair steps.
- [Heatline F20 - Overheat Fault](https://boilerandspares.co.uk/fault-codes/heatline-f20/) - Understand the Heatline F20 overheat fault, its likely causes and parts involved, then identify the right Boiler Spares replacement.
- [Heatline F22 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/heatline-f22/) - Fix Heatline F22 low water pressure with Boiler Spares fault advice, clear checks and parts guidance. Identify the cause and order spares.
- [Heatline F23 - Flow/Return Temperature Difference Too High](https://boilerandspares.co.uk/fault-codes/heatline-f23/) - Fix the Heatline F23 fault with clear checks for high flow/return temperature difference, plus likely causes and parts advice. See steps.
- [Heatline F24 - Water Circulation Fault](https://boilerandspares.co.uk/fault-codes/heatline-f24/) - Fix a Heatline F24 water circulation fault with clear checks, likely causes and spares guidance. Identify the issue and order parts.
- [Heatline F26 - Gas Valve Motor Fault](https://boilerandspares.co.uk/fault-codes/heatline-f26/) - Understand the Heatline F26 gas valve motor fault, its common causes and likely fixes, then check compatible Boiler Spares parts.
- [Heatline F27 - Flame Detection Fault](https://boilerandspares.co.uk/fault-codes/heatline-f27/) - Understand the Heatline F27 flame detection fault, common causes and practical fixes. Identify the issue fast and order the right spare.
- [Heatline F32 - Incorrect Air Pressure / Flue Fault](https://boilerandspares.co.uk/fault-codes/heatline-f32/) - Fix the Heatline F32 incorrect air pressure flue fault with clear checks, likely causes and parts guidance. Identify the issue fast.
- [Heatline F49 - eBUS Communication Fault](https://boilerandspares.co.uk/fault-codes/heatline-f49/) - Get clear fixes for the Heatline F49 eBUS communication fault code, with likely causes and repair steps. Identify the issue and order parts.
- [Heatline F72 - Flow/Return Sensor Temperature Drift](https://boilerandspares.co.uk/fault-codes/heatline-f72/) - Fix Heatline F72 flow/return sensor temperature drift with fault code advice, likely causes and parts support from Boiler Spares. Check yours now.
- [Heatline F73 - Heating Circuit Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/heatline-f73/) - Fix Heatline F73 heating circuit pressure sensor faults with clear checks, likely causes and the right boiler spares. See the steps.
- [Heatline F76 - Thermal Fuse Fault](https://boilerandspares.co.uk/fault-codes/heatline-f76/) - See what the Heatline F76 thermal fuse fault code means, common causes and practical checks so you can pinpoint the issue and fix it.
- [Heatline F83 - No Water Detected / Dry Fire](https://boilerandspares.co.uk/fault-codes/heatline-f83/) - Fix the Heatline F83 no water detected dry fire fault with clear checks, likely causes and parts guidance. Diagnose the issue now.
- [Heatline F00 - Flow Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/heatline-f00/) - Fix a Heatline F00 flow temperature sensor fault with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Heatline F01 - Flow NTC Fault](https://boilerandspares.co.uk/fault-codes/heatline-f01/) - Fix a Heatline F01 Flow NTC fault with clear checks, likely causes and parts advice from Boiler Spares. Use the guide to diagnose the issue.
- [Heatline F02 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/heatline-f02/) - Understand the Heatline F02 return NTC fault, its likely causes and the parts you may need, then check compatible Boiler Spares options.
- [Heatline F03 - Overheat](https://boilerandspares.co.uk/fault-codes/heatline-f03/) - Fix a Heatline F03 overheat fault with clear boiler error code guidance, likely causes and parts help. Check the fault and order spares.
- [Heatline F04 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/heatline-f04/) - Understand the Heatline F04 gas valve fault, common causes and fixes, with clear fault guidance to help you diagnose the issue. See steps.
- [Heatline F05 - Fan Fault](https://boilerandspares.co.uk/fault-codes/heatline-f05/) - Fix a Heatline F05 fan fault with clear checks, likely causes and parts guidance from Boiler Spares. Identify the issue and order spares.
- [Heatline F06 - Air Pressure Switch](https://boilerandspares.co.uk/fault-codes/heatline-f06/) - Understand Heatline F06 air pressure switch faults fast with clear checks, likely causes and compatible boiler spares. View the guide.
- [Heatline F07 - PCB Fault](https://boilerandspares.co.uk/fault-codes/heatline-f07/) - Understand Heatline F07 PCB faults, likely causes and parts needed, with clear guidance to diagnose the issue and order the right spare.
- [Heatline F08 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/heatline-f08/) - Fix the Heatline F08 low water pressure fault code with clear causes, checks and parts guidance. Identify the fault and order the right spares.
- [Heatline F09 - Pump Fault](https://boilerandspares.co.uk/fault-codes/heatline-f09/) - Understand the Heatline F09 pump fault with clear causes, fixes and parts guidance from Boiler Spares. Check the fault and order help.
- [Heatline F10 - DHW NTC Fault](https://boilerandspares.co.uk/fault-codes/heatline-f10/) - Understand the Heatline F10 DHW NTC fault code, its likely causes and fixes, with clear boiler fault guidance and the parts to check next.
- [Heatline F11 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/heatline-f11/) - Fix Heatline F11 condensate blocked faults with clear causes, checks and parts advice from Boiler Spares. Identify the issue and order the right part.
- [Heatline F12 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/heatline-f12/) - Get the Heatline F12 diverter valve fault explained, with likely causes and matching boiler spares. Check the fault and order the right part.
- [Heatline F13 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/heatline-f13/) - Fix Heatline F13 ignition failure with fault code guidance, likely causes and parts support from Boiler Spares. Check the code and order.
- [Heatline F14 - Flame Lost](https://boilerandspares.co.uk/fault-codes/heatline-f14/) - Understand the Heatline F14 flame lost fault code, its common causes and likely fixes, then check the right boiler spares to repair it.
- [Heatline F15 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/heatline-f15/) - Understand the Heatline F15 combustion fault, common causes and parts to check. Use our guide to diagnose the issue and order spares.
- [Heatline F16 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/heatline-f16/) - Understand the Heatline F16 pressure sensor fault, common causes and the right replacement parts. Diagnose the issue and order spares.
- [Heatline F17 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/heatline-f17/) - See why a Heatline boiler shows F17 after shutdown, what causes the flame signal, and the parts to check. Use the fault guide now.
- [Heatline F18 - External Thermostat Fault](https://boilerandspares.co.uk/fault-codes/heatline-f18/) - Fix the Heatline F18 external thermostat fault with clear fault-code guidance, likely causes and matching boiler spares. Order the right part.
- [Heatline F19 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/heatline-f19/) - Fix the Heatline F19 fault code with clear checks for rapid temperature rise, common causes and spare parts advice. Diagnose the issue now.
- [Heatline F21 - Flow/Return Reversed](https://boilerandspares.co.uk/fault-codes/heatline-f21/) - Fix Heatline F21 flow/return reversed faults with clear checks, likely causes and parts guidance. Identify the issue fast and order spares.
- [Heatline F25 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/heatline-f25/) - Understand the Heatline F25 outdoor sensor fault fast, with clear causes, likely fixes and parts guidance. Check the fault steps now.
- [Heatline F30 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/heatline-f30/) - Understand Heatline F30 eBUS fault codes, what causes them and how to fix them fast with clear checks. See the fault guide now.
- [Heatline F31 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/heatline-f31/) - Understand the Heatline F31 EEPROM fault code, its likely causes and fixes. Use our clear guide to diagnose the issue and order parts.
- [Heatline F33 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/heatline-f33/) - Understand the Heatline F33 mains voltage fault, common causes and practical checks before replacing parts. See the fault code guide.
- [Heatline F35 - Frost Protection](https://boilerandspares.co.uk/fault-codes/heatline-f35/) - Fix Heatline F35 frost protection faults with clear code meaning, likely causes and parts guidance from Boiler Spares. Check the fault now.
- [Biasi E27 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/biasi-e27/) - Fix a Biasi E27 combustion fault with clear causes, checks and parts advice from Boiler Spares. Identify the issue and order the right part.
- [Biasi E28 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/biasi-e28/) - Fix Biasi E28 flame detected after shutdown faults with clear causes, checks and parts guidance. Identify the issue fast and view spares.
- [Biasi E29 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/biasi-e29/) - Understand the Biasi E29 EEPROM fault, its likely causes and practical fixes. Check symptoms and parts advice from Boiler Spares.
- [Biasi E30 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/biasi-e30/) - See what the Biasi E30 mains voltage fault means, common causes and practical checks to help fix it. Use our guide to troubleshoot.
- [Biasi E31 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/biasi-e31/) - See why the Biasi E31 fault code appears when frost protection is active, what it means for your boiler, and the checks to take next.
- [Biasi E32 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/biasi-e32/) - Understand the Biasi E32 flue gas overheat fault, common causes and likely fixes, with clear guidance before you inspect boiler parts.
- [Biasi E33 - APS Fault](https://boilerandspares.co.uk/fault-codes/biasi-e33/) - Understand the Biasi E33 APS fault code, its likely causes and practical checks, then identify the right boiler spares to fix it.
- [Biasi E34 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/biasi-e34/) - See what causes a Biasi E34 pressure sensor fault, the checks to try, and the right replacement parts. Diagnose the issue and order spares.
- [Biasi E35 - Coding Plug Fault](https://boilerandspares.co.uk/fault-codes/biasi-e35/) - Understand the Biasi E35 coding plug fault, its likely causes and checks, with clear guidance to identify the issue and order the right part.
- [Biasi I1 - Ignition Failure / No Flame](https://boilerandspares.co.uk/fault-codes/biasi-i1/) - The most common Biasi fault code — the boiler has failed to ignite or lost its flame. Can also be caused by a frozen condensate pipe in winter.
- [Biasi E1 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/biasi-e1/) - Fix Biasi E1 low water pressure faults with clear, model-specific guidance from Boiler Spares. Check likely causes and order the right part.
- [Biasi E3 - Overheat Fault](https://boilerandspares.co.uk/fault-codes/biasi-e3/) - Fix a Biasi E3 overheat fault with clear causes, checks and spare part guidance from Boiler Spares. Identify the issue and order parts.
- [Biasi E4 - Fan Fault / Air Pressure Switch](https://boilerandspares.co.uk/fault-codes/biasi-e4/) - The fan is not operating correctly or the air pressure switch is not confirming airflow.
- [Biasi E5 - NTC Sensor Fault](https://boilerandspares.co.uk/fault-codes/biasi-e5/) - A temperature sensor (NTC thermistor) has a fault — either the flow or return sensor.
- [Biasi E6 - False Flame Detected](https://boilerandspares.co.uk/fault-codes/biasi-e6/) - Fix the Biasi E6 false flame detected fault code with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Biasi E7 - PCB / Electronics Fault](https://boilerandspares.co.uk/fault-codes/biasi-e7/) - The main PCB has detected an internal fault.
- [Biasi E9 - Flue/Exhaust Temperature Fault](https://boilerandspares.co.uk/fault-codes/biasi-e9/) - Understand the Biasi E9 flue or exhaust temperature fault code, common causes and likely fixes, then check the right boiler spares.
- [Biasi A1 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/biasi-a1/) - The gas valve has a fault — not responding to control commands correctly.
- [Biasi I2 - Overheat Lockout (Severe)](https://boilerandspares.co.uk/fault-codes/biasi-i2/) - Fix the Biasi I2 overheat lockout severe fault code with clear checks, likely causes and parts guidance. Identify the next repair step.
- [Navien 407 - Room Controller Communication Error](https://boilerandspares.co.uk/fault-codes/navien-407/) - Fix Navien 407 room controller communication errors with clear fault code checks, likely causes and parts guidance. Identify the issue now.
- [Biasi E2 - Safety Thermostat Activated](https://boilerandspares.co.uk/fault-codes/biasi-e2/) - Fix a Biasi E2 safety thermostat activated fault with clear causes, checks and parts advice from Boiler Spares. View the fault guide.
- [Biasi E8 - Flow Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/biasi-e8/) - Fix a Biasi E8 flow temperature sensor fault with clear checks, likely causes and parts guidance. Identify the issue and order the right spares.
- [Biasi E10 - Return Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/biasi-e10/) - Fix a Biasi E10 return temperature sensor fault with clear causes, checks and parts guidance. Identify the issue fast and order the right spare.
- [Biasi E11 - False Flame Signal](https://boilerandspares.co.uk/fault-codes/biasi-e11/) - Fix a Biasi E11 false flame signal fault with clear causes, checks and parts guidance from Boiler Spares. See the fault steps now.
- [Biasi E12 - DHW Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/biasi-e12/) - See what the Biasi E12 DHW temperature sensor fault code means, common causes, and the right spare parts to fix it. Check the fault guide.
- [Biasi E13 - Fan Speed Fault](https://boilerandspares.co.uk/fault-codes/biasi-e13/) - Understand the Biasi E13 fan speed fault, common causes and practical fixes to identify the issue quickly. Check the fault guide now.
- [Biasi E14 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/biasi-e14/) - Identify Biasi E14 gas valve faults fast with clear checks, likely causes and parts guidance from Boiler Spares. Use the guide now.
- [Biasi E15 - PCB Fault](https://boilerandspares.co.uk/fault-codes/biasi-e15/) - Understand the Biasi E15 PCB fault, see likely causes and matching parts, and choose the right replacement fast. View the details.
- [Biasi E16 - Condensate Trap Full / Blocked](https://boilerandspares.co.uk/fault-codes/biasi-e16/) - Fix a Biasi E16 fault caused by a full or blocked condensate trap with clear checks, parts advice and repair steps. Diagnose the issue now.
- [Biasi E17 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/biasi-e17/) - Fix the Biasi E17 low water pressure fault with clear causes, practical checks and parts guidance from Boiler Spares. Read the guide.
- [Navien 005 - Abnormal Ignition](https://boilerandspares.co.uk/fault-codes/navien-005/) - Understand Navien 005 abnormal ignition fault code, common causes and likely fixes with clear boiler fault guidance. Check the steps now.
- [Navien 006 - False Flame Signal](https://boilerandspares.co.uk/fault-codes/navien-006/) - Understand Navien 006 false flame signal fault code causes, checks and fix steps with clear fault guidance. Use the code guide now.
- [Navien 007 - Fan Fault](https://boilerandspares.co.uk/fault-codes/navien-007/) - Understand Navien 007 fan faults, what causes them and how to fix them with clear steps from Boiler Spares. Check the fault and order parts.
- [Navien 008 - Exhaust Blockage](https://boilerandspares.co.uk/fault-codes/navien-008/) - Understand Navien 008 exhaust blockage fault code, common causes and fixes from Boiler Spares. Check symptoms and order the right parts.
- [Navien 009 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/navien-009/) - Fix Navien 009 air pressure switch fault code with clear causes, checks and parts advice from Boiler Spares. Identify the right next step.
- [Navien 013 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/navien-013/) - Fix Navien 013 low water pressure faults with clear checks, likely causes and parts guidance from Boiler Spares. See the fault code steps.
- [Navien 014 - Pump Fault](https://boilerandspares.co.uk/fault-codes/navien-014/) - Fix a Navien 014 pump fault with clear checks, likely causes and parts advice from Boiler Spares. Identify the issue fast and order the right part.
- [Navien 017 - PCB Fault](https://boilerandspares.co.uk/fault-codes/navien-017/) - Understand the Navien 017 PCB fault, what causes it and how to fix it with clear, practical guidance. Check the fault code steps now.
- [Navien 018 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/navien-018/) - Fix Navien 018 overheat protection fault code fast with clear causes, checks and part guidance from Boiler Spares. See the steps now.
- [Navien 019 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/navien-019/) - Fix Navien 019 condensate blocked fault code with clear checks, likely causes and parts guidance. Identify the fault and order spares.
- [Navien 020 - DHW Overheat](https://boilerandspares.co.uk/fault-codes/navien-020/) - Fix Navien 020 DHW overheat fault code with clear causes, checks and parts guidance from Boiler Spares. Identify the issue fast.
- [Navien 028 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/navien-028/) - Get a clear explanation of the Navien 028 diverter valve fault code, common causes and fixes, with practical checks before you order parts.
- [Navien 031 - Flow Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/navien-031/) - Fix Navien 031 flow sensor short circuit faults with clear causes, checks and parts guidance from Boiler Spares. View the fault code steps.
- [Navien 033 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/navien-033/) - Fix a Navien 033 gas valve fault with clear checks, likely causes and spare parts guidance. Use the guide to identify the next step.
- [Navien 034 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/navien-034/) - Fix Navien 034 return sensor faults with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order the right part.
- [Navien 035 - Flow Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/navien-035/) - Fix Navien 035 flow sensor open circuit faults with clear checks, likely causes and spares guidance. See the fault code steps now.
- [Navien 038 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/navien-038/) - Understand Navien 038 combustion fault code, common causes and fixes from Boiler Spares. Check symptoms and order the right parts.
- [Navien 040 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/navien-040/) - Understand Navien 040 eBUS fault codes fast with clear causes, checks and fixes from Boiler Spares. Identify the issue and order parts.
- [Navien 041 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/navien-041/) - Fix Navien 041 Frost Protection Active faults with clear causes, checks and part guidance from Boiler Spares. See the fault code steps.
- [Navien 042 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/navien-042/) - Fix Navien 042 pressure sensor faults with clear checks, likely causes and parts guidance from Boiler Spares. Diagnose the issue now.
- [Biasi E18 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/biasi-e18/) - Understand the Biasi E18 gas valve fault, common causes and repair options to diagnose issues faster. See the fault guide now.
- [Biasi E19 - Pump Fault](https://boilerandspares.co.uk/fault-codes/biasi-e19/) - See what the Biasi E19 pump fault code means, common causes, and the parts you may need to fix it. Check symptoms and order spares.
- [Biasi E20 - PCB Communication Error](https://boilerandspares.co.uk/fault-codes/biasi-e20/) - Fix Biasi E20 PCB communication errors with clear fault checks, likely causes and spare part guidance. See the repair steps now.
- [Biasi E21 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/biasi-e21/) - Fix a Biasi E21 low gas pressure fault with clear checks, likely causes and part guidance. See the fault code steps and order spares.
- [Biasi E22 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/biasi-e22/) - Understand the Biasi E22 diverter valve fault, what causes it, and how to fix it with clear fault guidance. Check the next steps.
- [Biasi E23 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/biasi-e23/) - Fix a Biasi E23 fault code caused by rapid temperature rise with clear checks, likely causes and parts advice. See the troubleshooting steps.
- [Biasi E24 - Flow/Return Differential Fault](https://boilerandspares.co.uk/fault-codes/biasi-e24/) - Fix the Biasi E24 flow/return differential fault with clear causes, checks and parts guidance from Boiler Spares. Identify the fix.
- [Biasi E25 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/biasi-e25/) - Understand the Biasi E25 outdoor sensor fault, what causes it, and how to check parts fast with Boiler Spares. See the likely fix.
- [Biasi E26 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/biasi-e26/) - Fix Biasi E26 eBUS faults with clear code meanings, likely causes and practical checks. Use the guide to identify the issue fast.
- [Ravenheat E02 - Pump Circulation Problem](https://boilerandspares.co.uk/fault-codes/ravenheat-e02/) - On Ravenheat CS/WH/HE models, E02 indicates a problem with the pump circulation — the pump may be failing or seized.
- [Ravenheat E03 - Flow Sensor Damaged](https://boilerandspares.co.uk/fault-codes/ravenheat-e03/) - The flow temperature sensor has failed or has a wiring fault.
- [Ravenheat E04 - DHW Sensor Damaged](https://boilerandspares.co.uk/fault-codes/ravenheat-e04/) - On CS/WH/HE models, E04 indicates the domestic hot water sensor has failed.
- [Ravenheat E05 - Fan Fault — No Signal](https://boilerandspares.co.uk/fault-codes/ravenheat-e05/) - The fan is not running or there is no fan speed signal. The fan may be failing or have a wiring fault.
- [Ravenheat E06 - CH Sensor Overheating](https://boilerandspares.co.uk/fault-codes/ravenheat-e06/) - Fix Ravenheat E06 CH sensor overheating faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Ravenheat E08 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/ravenheat-e08/) - System water pressure is below the safe minimum on Ravenheat CS/WH/HE boilers.
- [Ravenheat E09 - Overheat Sensor Overheating](https://boilerandspares.co.uk/fault-codes/ravenheat-e09/) - The overheat thermostat sensor has detected a dangerous temperature.
- [Ravenheat E10 - High Water Pressure](https://boilerandspares.co.uk/fault-codes/ravenheat-e10/) - The system water pressure is too high on Ravenheat boilers.
- [Ravenheat E22 - Flue Sensor Overheating](https://boilerandspares.co.uk/fault-codes/ravenheat-e22/) - The flue gas sensor has detected an overtemperature condition in the flue.
- [Ravenheat E23 - Flue Sensor Damaged](https://boilerandspares.co.uk/fault-codes/ravenheat-e23/) - The flue temperature sensor has failed or has a wiring fault.
- [Ravenheat E25 - Heat Exchanger Frozen](https://boilerandspares.co.uk/fault-codes/ravenheat-e25/) - The main heat exchanger has frozen. This typically occurs when the boiler is in an unheated space during very cold weather.
- [Ravenheat E46 - Water Pressure Sensor Error](https://boilerandspares.co.uk/fault-codes/ravenheat-e46/) - Fix a Ravenheat E46 water pressure sensor error with clear fault advice, likely causes and parts help. Check the fault and order spares.
- [Ravenheat 01 - Ignition Failure (CSI)](https://boilerandspares.co.uk/fault-codes/ravenheat-01/) - On Ravenheat CSI boilers, code 01 indicates the boiler has failed to ignite — check gas valve, fan, ignition control board and cables.
- [Ravenheat 28 - Low Water Pressure / Pump Fault (CSI)](https://boilerandspares.co.uk/fault-codes/ravenheat-28/) - See causes and fixes for Ravenheat 28 low water pressure and pump faults on CSI boilers, with parts guidance. Check the fault now.
- [Ravenheat 04 - Overheat Thermostat Fault (CSI)](https://boilerandspares.co.uk/fault-codes/ravenheat-04/) - On Ravenheat CSI boilers, code 04 indicates the overheat thermostat needs checking.
- [Navien 003 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/navien-003/) - The boiler has failed to ignite — manual reset required. The most common Navien fault code. On Navien boilers, a frozen condensate pipe in winter is a common cause.
- [Navien 004 - False Flame (Auto-Reset)](https://boilerandspares.co.uk/fault-codes/navien-004/) - The boiler has detected a flame signal when not expected. This version auto-resets but if it recurs, the gas valve or PCB needs checking.
- [Navien 012 - Flame Loss During Operation](https://boilerandspares.co.uk/fault-codes/navien-012/) - Fix Navien 012 flame loss during operation with clear fault code guidance, likely causes and parts advice. Check symptoms and order spares.
- [Navien 016 - Heat Exchanger Overheated](https://boilerandspares.co.uk/fault-codes/navien-016/) - The primary heat exchanger has detected an overtemperature condition. Manual reset required.
- [Navien 030 - Abnormal Exhaust Temperature](https://boilerandspares.co.uk/fault-codes/navien-030/) - The exhaust (flue gas) temperature is abnormal — either too high or there is a flue blockage. Manual reset required.
- [Navien 046 - Heat Exchanger Overheating (Auto-Reset)](https://boilerandspares.co.uk/fault-codes/navien-046/) - Fix Navien 046 heat exchanger overheating auto-reset faults with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Navien 109 - Fan Error](https://boilerandspares.co.uk/fault-codes/navien-109/) - See what Navien 109 fan error means, common causes and likely fixes, with boiler spares support. Check the fault and order the right part.
- [Navien 110 - Exhaust Blockage / Condensate Blockage](https://boilerandspares.co.uk/fault-codes/navien-110/) - The exhaust system or condensate drain is blocked. On Navien boilers this is the specific code for a blocked or frozen condensate pipe — the most common winter fault.
- [Navien 127 - Air Pressure Switch (APS) Issue](https://boilerandspares.co.uk/fault-codes/navien-127/) - The air pressure switch is not operating correctly — it is not confirming adequate airflow before ignition. Reset and check for flue obstructions.
- [Navien 205 - Heating Supply Thermistor Fault](https://boilerandspares.co.uk/fault-codes/navien-205/) - The heating supply (flow) thermistor has an open or short circuit fault. The boiler may auto-reset.
- [Navien 218 - Heating Return Thermistor Fault](https://boilerandspares.co.uk/fault-codes/navien-218/) - Fix Navien 218 heating return thermistor faults with clear causes, checks and parts guidance. Identify the issue fast and order the right spares.
- [Navien 302 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/navien-302/) - Fix Navien 302 low water pressure faults with clear checks, likely causes and parts guidance. Identify the issue fast and order the right spares.
- [Navien 352 - High Water Pressure](https://boilerandspares.co.uk/fault-codes/navien-352/) - The system water pressure is too high. The boiler should auto-reset once pressure drops.
- [Navien 594 - EEPROM Error (PCB)](https://boilerandspares.co.uk/fault-codes/navien-594/) - There is a memory fault on the main PCB. Contact an engineer — this cannot be resolved by resetting.
- [Navien 001 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/navien-001/) - Understand Navien 001 ignition failure causes, checks and fixes with clear fault code guidance from Boiler Spares. See the troubleshooting steps.
- [Navien 002 - Flame Loss During Operation](https://boilerandspares.co.uk/fault-codes/navien-002/) - Fix Navien 002 flame loss during operation with clear fault code checks, likely causes and spare part guidance. View the troubleshooting steps.
- [Navien 010 - Abnormal Exhaust Temperature](https://boilerandspares.co.uk/fault-codes/navien-010/) - Fix Navien 010 abnormal exhaust temperature faults with clear checks, likely causes and parts advice. Diagnose the issue and order spares.
- [Navien 011 - Abnormal Air Pressure](https://boilerandspares.co.uk/fault-codes/navien-011/) - Fix Navien 011 abnormal air pressure fault code with clear checks, likely causes and parts advice from Boiler Spares. See the steps now.
- [Navien 015 - PCB Fault](https://boilerandspares.co.uk/fault-codes/navien-015/) - Fix Navien 015 PCB faults with clear code checks, likely causes and parts guidance from Boiler Spares. See the steps and order the right part.
- [Navien 027 - Low Water Flow](https://boilerandspares.co.uk/fault-codes/navien-027/) - Fix Navien 027 low water flow faults with clear causes, practical checks and parts guidance from Boiler Spares. See the fault code steps.
- [Navien 032 - DHW Thermistor Fault](https://boilerandspares.co.uk/fault-codes/navien-032/) - Understand the Navien 032 DHW thermistor fault, what causes it, and how to fix it fast with clear guidance on parts and next steps.
- [Navien 036 - Heating Thermistor Fault](https://boilerandspares.co.uk/fault-codes/navien-036/) - Fix Navien 036 heating thermistor fault codes fast with clear fault advice and boiler spares support. Check causes and order the right part.
- [Ravenheat E01 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/ravenheat-e01/) - Fix Ravenheat E01 ignition failure faults with clear boiler checks, likely causes and part guidance from Boiler Spares. See the code steps.
- [Ravenheat E07 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/ravenheat-e07/) - Understand Ravenheat E07 overheat protection fault code, likely causes and parts needed to fix it. Check symptoms and order spares.
- [Ravenheat E11 - PCB Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e11/) - Understand Ravenheat E11 PCB faults with clear causes, checks and repair options from Boiler Spares. Identify the issue and order parts.
- [Ravenheat E12 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e12/) - Fix a Ravenheat E12 return NTC fault with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order spares.
- [Ravenheat E13 - DHW NTC Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e13/) - Fix Ravenheat E13 DHW NTC faults with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order the right part.
- [Ravenheat E14 - Pump Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e14/) - Fix a Ravenheat E14 pump fault with clear checks, likely causes and matching boiler spares. Identify the issue fast and order parts.
- [Ravenheat E15 - Fan Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e15/) - Understand the Ravenheat E15 fan fault, common causes and repair options with clear guidance. Check the symptoms and fix your boiler.
- [Ravenheat E16 - Air Pressure Switch](https://boilerandspares.co.uk/fault-codes/ravenheat-e16/) - Fix a Ravenheat E16 air pressure switch fault with clear causes, checks and part guidance from Boiler Spares. See the fault steps now.
- [Ravenheat E17 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/ravenheat-e17/) - Fix the Ravenheat E17 low water pressure fault with clear causes, checks and parts guidance from Boiler Spares. Identify the issue fast.
- [Ravenheat E18 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e18/) - Understand the Ravenheat E18 gas valve fault with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and fix it.
- [Ravenheat E19 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/ravenheat-e19/) - Fix Ravenheat E19 condensate blocked fault codes with clear fault checks, likely causes and parts guidance. Identify the issue and order spares.
- [Ravenheat E20 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e20/) - Fix Ravenheat E20 diverter valve fault codes with clear causes, part guidance and fast boiler spares support. Check the fault and order parts.
- [Ravenheat E21 - Flame Lost](https://boilerandspares.co.uk/fault-codes/ravenheat-e21/) - Fix Ravenheat E21 flame lost faults with clear causes, tested checks and the right spare parts. See the fault code guide and order parts.
- [Ravenheat E24 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e24/) - Understand the Ravenheat E24 combustion fault, common causes and likely fixes with clear guidance. Check symptoms and next steps.
- [Ravenheat E26 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/ravenheat-e26/) - See what the Ravenheat E26 fault code means, common causes of rapid temperature rise, and the parts to check before you replace anything.
- [Ravenheat E27 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/ravenheat-e27/) - Fix a Ravenheat E27 pressure sensor fault with clear checks, likely causes and part guidance from Boiler Spares. See the steps now.
- [Keston E01 - Ignition Failure — 5 Attempts](https://boilerandspares.co.uk/fault-codes/keston-e01/) - The boiler has attempted to light 5 times and failed. The most common Keston fault code.
- [Keston E02 - False Flame Detected (C36/CSI)](https://boilerandspares.co.uk/fault-codes/keston-e02/) - Fix Keston E02 false flame detected faults with clear C36/CSI guidance, likely causes and part checks. See the fault code steps.
- [Keston E03 - Boiler Overheat](https://boilerandspares.co.uk/fault-codes/keston-e03/) - The boiler has overheated — check for closed valves, air in system, or incorrect water pressure.
- [Keston E05 - Fan Failure](https://boilerandspares.co.uk/fault-codes/keston-e05/) - Fix Keston E05 fan failure with clear fault-code guidance, likely causes and parts advice from Boiler Spares. Check the code and order parts.
- [Keston E07 - Flue Overheat](https://boilerandspares.co.uk/fault-codes/keston-e07/) - The flue temperature has exceeded safe limits. The flue temperature should be no more than 10°C above the return temperature — a higher reading suggests heat exchanger issues.
- [Keston E08 - Flame Circuit Error](https://boilerandspares.co.uk/fault-codes/keston-e08/) - There is a fault in the flame monitoring circuit — possibly the control box.
- [Keston E09 - Gas Valve Drive Error](https://boilerandspares.co.uk/fault-codes/keston-e09/) - Understand the Keston E09 gas valve drive error, its likely causes and fixes, with clear fault guidance. Check the next steps now.
- [Keston E23 - Water Filling Error](https://boilerandspares.co.uk/fault-codes/keston-e23/) - Fix Keston E23 water filling errors with clear fault code guidance, likely causes and parts advice. Identify the issue and order spares.
- [Keston E24 - Water Pressure Lost 4 Times in 24 Hours](https://boilerandspares.co.uk/fault-codes/keston-e24/) - The system has lost pressure 4 times within 24 hours — indicating a possible leak.
- [Keston E26 - Flame Drop Out](https://boilerandspares.co.uk/fault-codes/keston-e26/) - The boiler flame has dropped out during operation. Check for flue obstruction, blocked condensate drain, or low gas supply (especially on LPG).
- [Keston E30 - Flow Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/keston-e30/) - Fix a Keston E30 flow sensor short circuit with fault code guidance, likely causes and parts help. Check symptoms and order spares.
- [Keston E31 - Flow Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/keston-e31/) - The flow temperature sensor circuit is open — the sensor is not connected or has failed.
- [Keston E37 - Water Pressure Error](https://boilerandspares.co.uk/fault-codes/keston-e37/) - The water pressure is too low — increase system pressure using the filling loop.
- [Keston E40 - Water Pressure Too High](https://boilerandspares.co.uk/fault-codes/keston-e40/) - The system water pressure is too high — above 3 bar.
- [Keston E43 - Return Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/keston-e43/) - Fix the Keston E43 return sensor short circuit fault with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Keston E44 - Return Sensor Open Circuit (C55)](https://boilerandspares.co.uk/fault-codes/keston-e44/) - The return temperature sensor circuit is open on the C55 boiler.
- [Keston E18 - Flow Overheat (C40/C55)](https://boilerandspares.co.uk/fault-codes/keston-e18/) - On Keston C40 and C55 boilers, E18 indicates the flow temperature has exceeded safe limits. Check water circulation.
- [Keston E44 (C36) - Low Water Pressure (C36)](https://boilerandspares.co.uk/fault-codes/keston-e44-c36/) - Fix Keston E44 (C36) low water pressure faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Keston E04 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/keston-e04/) - Fix a Keston E04 return NTC fault with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order spares.
- [Keston E06 - Fan Fault](https://boilerandspares.co.uk/fault-codes/keston-e06/) - Understand the Keston E06 fan fault, its common causes and likely fixes with clear guidance from Boiler Spares. Check the code now.
- [Keston E10 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/keston-e10/) - Understand the Keston E10 gas valve fault, its likely causes and checks to try before ordering the right Boiler Spares part. See fixes.
- [Keston E11 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/keston-e11/) - Understand the Keston E11 overheat protection fault code, its likely causes and fixes, with parts advice to help you repair the boiler.
- [Keston E12 - PCB Fault](https://boilerandspares.co.uk/fault-codes/keston-e12/) - See what the Keston E12 PCB fault code means, common causes, and practical checks to narrow the issue. Read the guide and identify next steps.
- [Keston E13 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/keston-e13/) - Fix the Keston E13 condensate blocked fault code with clear checks, common causes and parts guidance. Identify the fault and order spares.
- [Keston E14 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/keston-e14/) - Fix a Keston E14 low water pressure fault with clear causes, checks and parts guidance from Boiler Spares. View the code and next steps.
- [Keston E15 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/keston-e15/) - Understand the Keston E15 DHW sensor fault code, its likely causes and fixes, with clear guidance to identify parts and order replacements.
- [Keston E16 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/keston-e16/) - Understand Keston E16 diverter valve faults, what causes them, and how to fix them fast with clear guidance. Check the fault details now.
- [Keston E17 - Pump Fault](https://boilerandspares.co.uk/fault-codes/keston-e17/) - Understand the Keston E17 pump fault with clear causes, checks and parts guidance from Boiler Spares. Identify the fix and order spares.
- [Keston E19 - Flame Lost](https://boilerandspares.co.uk/fault-codes/keston-e19/) - Understand the Keston E19 fault code, its common causes and practical fixes. Identify the issue faster and see the next steps.
- [Keston E20 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/keston-e20/) - Understand the Keston E20 air pressure switch fault, common causes and fix options, with practical checks. Diagnose the issue now.
- [Keston E21 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/keston-e21/) - Understand the Keston E21 fault code for rapid temperature rise, its likely causes and fixes, then check the right boiler spares.
- [Keston E22 - Flow/Return Differential](https://boilerandspares.co.uk/fault-codes/keston-e22/) - Fix the Keston E22 flow/return differential fault code with clear causes, checks and part guidance. Identify the fault and order spares.
- [Keston E25 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/keston-e25/) - Understand the Keston E25 outdoor sensor fault, common causes and fixes, with clear troubleshooting steps. Identify the issue now.
- [Keston E27 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/keston-e27/) - See what the Keston E27 mains voltage fault code means, likely causes and practical fixes, then check the right Boiler Spares parts.
- [Keston E28 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/keston-e28/) - Understand Keston E28 eBUS fault codes fast with clear causes, fixes and parts guidance. Diagnose the issue and choose the right next step.
- [Keston E29 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/keston-e29/) - Understand the Keston E29 combustion fault code, common causes and fix steps with clear guidance. Check the code and order parts.
- [Keston E32 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/keston-e32/) - Understand the Keston E32 EEPROM error, what causes it, and the parts you may need to fix it. Check the fault and order spares.
- [Keston E33 - Frost Protection](https://boilerandspares.co.uk/fault-codes/keston-e33/) - Fix a Keston E33 frost protection fault code with clear causes, checks and parts guidance. Identify the issue fast and order the right spares.
- [Keston E34 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/keston-e34/) - Fix the Keston E34 flame detected after shutdown fault with clear checks, likely causes and parts guidance. See the fault code steps.
- [Keston E35 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/keston-e35/) - Understand the Keston E35 flue gas overheat fault code, its likely causes and fixes, with clear advice to help you diagnose the problem fast.
- [Saunier Duval F1 - Ignition Failure / Lockout](https://boilerandspares.co.uk/fault-codes/saunier-duval-f1/) - Fix Saunier Duval F1 ignition failure or lockout with fault code causes, checks and parts guidance. Identify the issue and order spares.
- [Saunier Duval F4 - Flame Lost During Operation](https://boilerandspares.co.uk/fault-codes/saunier-duval-f4/) - The boiler ignited but then lost the flame during operation. On some Saunier Duval models, F4 is also used for a second type of ignition fault.
- [Saunier Duval F5 - Overheat Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f5/) - The overheat safety thermostat has operated on the boiler. Usually caused by poor circulation, low water pressure, or air in the system.
- [Saunier Duval F6 - CH Flow Thermistor Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f6/) - The central heating flow temperature sensor has a fault.
- [Saunier Duval F7 - DHW Thermistor Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f7/) - The domestic hot water temperature sensor has a fault.
- [Saunier Duval F9 - Water Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f9/) - The water pressure sensor has a faulty connection or has failed. Check wiring.
- [Saunier Duval F10 - CH Return Thermistor Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f10/) - The central heating return temperature sensor has a fault.
- [Saunier Duval F16 - False Flame After Burner Stop](https://boilerandspares.co.uk/fault-codes/saunier-duval-f16/) - Fix the Saunier Duval F16 false flame after burner stop fault with clear checks, likely causes and parts guidance. Identify the next step.
- [Saunier Duval F17 - Low Mains Voltage](https://boilerandspares.co.uk/fault-codes/saunier-duval-f17/) - See what low mains voltage on a Saunier Duval F17 means, common causes and likely fixes. Check the fault code and identify the next step.
- [Saunier Duval F19 - CH Thermistor Disconnected](https://boilerandspares.co.uk/fault-codes/saunier-duval-f19/) - The central heating temperature thermistor appears to have become unplugged or disconnected.
- [Saunier Duval F20 - Software Incompatibility](https://boilerandspares.co.uk/fault-codes/saunier-duval-f20/) - The user interface or main board has incorrect or incompatible software.
- [Saunier Duval F23 - Water Circulation Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f23/) - Insufficient water circulation detected — possible pump failure.
- [Saunier Duval F26 - Maximum Delta Temperature](https://boilerandspares.co.uk/fault-codes/saunier-duval-f26/) - The temperature difference between flow and return is too great — water circulation fault or flow/return connections swapped.
- [Saunier Duval F28 - Permanent Flow/Return Sensor Drift (Thema)](https://boilerandspares.co.uk/fault-codes/saunier-duval-f28/) - On Saunier Duval Thema boilers, F28 indicates a permanent temperature drift between the flow and return sensors — possible sensor fault.
- [Saunier Duval F29 - Thermal Fuse Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f29/) - The thermal fuse on the heat exchanger has activated — requires heat exchanger replacement.
- [Saunier Duval F14 - Flow Temperature Above 95°C](https://boilerandspares.co.uk/fault-codes/saunier-duval-f14/) - The flow temperature has exceeded 95°C — a serious overheat condition.
- [Saunier Duval F25 - Flow Temperature Rising Too Fast](https://boilerandspares.co.uk/fault-codes/saunier-duval-f25/) - The flow temperature is rising at an unsafe rate — possible pump failure or severe airlock.
- [Main Heating E16 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/main-heating-e16/) - Fix Main Heating E16 condensate blocked fault code with clear checks, likely causes and parts advice from Boiler Spares. See the fault guide.
- [Main Heating E17 - Fan Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e17/) - See what the Main Heating E17 fan fault code means, common causes and practical checks to help diagnose the issue. Check the fault guide.
- [Main Heating E18 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e18/) - See what an E18 gas valve fault means, common causes and the parts you may need, with clear fixes and next steps. Check the guide.
- [Main Heating E19 - Pump Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e19/) - Understand the Main Heating E19 pump fault code, its common causes and fixes, then check the right Boiler Spares parts to repair it.
- [Main Heating E21 - PCB Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e21/) - Buy Main Heating E21 PCB fault boiler spares with fast UK delivery and model-matched parts. Check the fault code and order the right PCB now.
- [Main Heating E22 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/main-heating-e22/) - Understand the Main Heating E22 low gas pressure fault code, common causes and practical checks, then identify the right Boiler Spares parts.
- [Main Heating E23 - Air Pressure Switch](https://boilerandspares.co.uk/fault-codes/main-heating-e23/) - Fix the Main Heating E23 air pressure switch fault with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Main Heating E24 - Flame Instability](https://boilerandspares.co.uk/fault-codes/main-heating-e24/) - Fix Main Heating E24 flame instability with clear fault code guidance, likely causes and parts help from Boiler Spares. Check the fix.
- [Main Heating E25 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/main-heating-e25/) - Fix Main Heating E25 overheat protection fault code with clear causes, checks and parts guidance from Boiler Spares. Identify the fault fast.
- [Main Heating E26 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/main-heating-e26/) - See what the Main Heating E26 fault code means, why rapid temperature rise happens, and the checks to take next. Identify the fault fast.
- [Main Heating E27 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e27/) - Fix Main Heating E27 pressure sensor faults with clear code guidance, likely causes and parts support. Check the fault and order spares.
- [Main Heating E30 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/main-heating-e30/) - Understand the Main Heating E30 fault code and frost protection mode, with clear checks and likely causes. See the fault guide now.
- [Main Heating E31 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e31/) - Fix the Main Heating E31 eBUS fault with clear checks, likely causes and parts advice from Boiler Spares. See the guide and identify the issue.
- [Main Heating E32 - Combustion Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e32/) - Understand the Main Heating E32 combustion fault code, its likely causes and fix options, then check the parts you may need.
- [Saunier Duval F2 - Flame Supervision Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f2/) - Fix a Saunier Duval F2 flame supervision fault with clear causes, checks and parts guidance. Identify the issue fast and order spares.
- [Saunier Duval F3 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f3/) - Understand the Saunier Duval F3 return NTC fault, its common causes and likely fixes. Check symptoms, identify parts and order spares.
- [Saunier Duval F8 - Slow Temperature Rise](https://boilerandspares.co.uk/fault-codes/saunier-duval-f8/) - Understand Saunier Duval F8 slow temperature rise faults, common causes and spare parts needed to fix the issue. Identify the right part.
- [Saunier Duval F11 - Flow NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/saunier-duval-f11/) - Fix a Saunier Duval F11 flow NTC short circuit with clear fault checks, likely causes and spare part guidance. Diagnose the issue now.
- [Saunier Duval F12 - Return NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/saunier-duval-f12/) - Fix the Saunier Duval F12 return NTC short circuit fault with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Saunier Duval F13 - DHW NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/saunier-duval-f13/) - Fix Saunier Duval F13 DHW NTC short circuit faults with clear diagnosis, likely causes and part guidance. Check the code and order spares.
- [Saunier Duval F15 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f15/) - Fix Saunier Duval F15 gas valve faults with clear code guidance, likely causes and parts support from Boiler Spares. Check the fault now.
- [Saunier Duval F18 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/saunier-duval-f18/) - Fix Saunier Duval F18 low water pressure faults with clear causes, reset steps and pressure checks. Identify the issue fast and follow the guide.
- [Saunier Duval F21 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/saunier-duval-f21/) - Fix a Saunier Duval F21 condensate blocked fault with clear fault code advice, likely causes and parts help. Check the steps now.
- [Saunier Duval F22 - Pump Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f22/) - See what the Saunier Duval F22 pump fault means, common causes, and the parts often linked to the issue, then check the right boiler spares.
- [Saunier Duval F24 - PCB Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f24/) - Understand Saunier Duval F24 PCB faults, common causes and repair options with clear guidance from Boiler Spares. Check the fault details.
- [Saunier Duval F27 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/saunier-duval-f27/) - Fix the Saunier Duval F27 fault with clear checks for flame detection after shutdown, plus likely causes and parts guidance. View the steps.
- [Saunier Duval F30 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f30/) - Fix a Saunier Duval F30 air pressure switch fault with clear checks, likely causes and matching boiler spares. Identify the part and order.
- [Saunier Duval F31 - Fan Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f31/) - What the Saunier Duval F31 fan fault means, common causes, and the parts often needed to fix it. Check symptoms and identify the fault.
- [Saunier Duval F32 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/saunier-duval-f32/) - Fix Saunier Duval F32 overheat protection fault code with clear causes, checks and part guidance from Boiler Spares. See the steps.
- [Saunier Duval F33 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/saunier-duval-f33/) - Fix Saunier Duval F33 flue gas overheat faults with clear causes, checks and parts guidance from Boiler Spares. Identify the issue fast.
- [Saunier Duval F34 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/saunier-duval-f34/) - Fix Saunier Duval F34 diverter valve fault codes with clear fault guidance and matching boiler spares. Check the code and order the right part.
- [Saunier Duval F35 - Combustion Quality](https://boilerandspares.co.uk/fault-codes/saunier-duval-f35/) - Understand Saunier Duval F35 combustion quality faults fast with clear causes, checks and parts guidance. Identify the fix and order spares.
- [Intergas E11 - PCB / Electronics Fault](https://boilerandspares.co.uk/fault-codes/intergas-e11/) - Fix Intergas E11 PCB and electronics faults with clear fault code guidance and matching Boiler Spares parts. Check symptoms and order.
- [Intergas E13 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/intergas-e13/) - The gas valve has a fault — it may not be opening or closing correctly, or has a wiring fault.
- [Intergas E14 - Flue Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/intergas-e14/) - The flue gas temperature sensor has failed or has a wiring fault.
- [Intergas E16 - Maximum Resets Exceeded](https://boilerandspares.co.uk/fault-codes/intergas-e16/) - The boiler has exceeded its maximum number of consecutive resets. It will not restart until the underlying fault is resolved.
- [Intergas E17 - Condensate Pump Fault](https://boilerandspares.co.uk/fault-codes/intergas-e17/) - On Intergas models fitted with a condensate pump, E17 indicates the pump has a fault or is not operating.
- [Intergas E20 - DHW Flow Rate Fault](https://boilerandspares.co.uk/fault-codes/intergas-e20/) - The domestic hot water flow rate is outside the expected range — either too low or too high.
- [Main Heating E119 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/main-heating-e119/) - System pressure has dropped below 0.5 bar. Main Heating boilers share the same fault code system as Baxi — E119 cannot be cleared by resetting alone.
- [Main Heating E133 - Ignition Failure / Frozen Condensate](https://boilerandspares.co.uk/fault-codes/main-heating-e133/) - The boiler has failed to ignite. Identical to Baxi E133 — Main Heating shares the BDR Thermea fault code system. In winter, commonly caused by a frozen condensate pipe.
- [Main Heating E110 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/main-heating-e110/) - The boiler has overheated and the safety thermostat has triggered.
- [Main Heating E125 - Primary Circuit Circulation Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e125/) - Insufficient water circulation through the primary heating circuit.
- [Main Heating E160 - Fan Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e160/) - The boiler fan has a fault — not running, running slowly, or speed sensor failure.
- [Main Heating E168 - PCB Lockout / Unspecified Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e168/) - Fix Main Heating E168 PCB lockout or unspecified fault with clear fault-code guidance and boiler spares support. Check the fix now.
- [Main Heating E128 - Loss of Flame During Operation](https://boilerandspares.co.uk/fault-codes/main-heating-e128/) - The boiler has lost its flame 12 times during operation, triggering a safety lockout.
- [Main Heating E130 - Flue Thermostat Tripped](https://boilerandspares.co.uk/fault-codes/main-heating-e130/) - Fix the Main Heating E130 flue thermostat fault with clear causes, checks and reset guidance. Identify the issue fast and order the right part.
- [Main Heating E270 - Dry Fire Detected](https://boilerandspares.co.uk/fault-codes/main-heating-e270/) - Fix Main Heating E270 dry fire detected faults with clear checks, likely causes and parts guidance. Diagnose the issue and order spares.
- [Main Heating E28 - Frozen Condensate / Flue Thermistor Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e28/) - In cold weather, E28 on Main Heating boilers indicates a frozen condensate pipe. In warmer conditions, may indicate a flue thermistor fault.
- [Main Heating E09 - Gas Valve Connection Error](https://boilerandspares.co.uk/fault-codes/main-heating-e09/) - Fix Main Heating E09 gas valve connection errors with clear fault code guidance and the right spares. Check symptoms and order parts.
- [Main Heating E20 - CH NTC Sensor Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e20/) - Central heating thermistor sensor fault on Main Heating boilers.
- [Main Heating E40 - CH Return Sensor Error](https://boilerandspares.co.uk/fault-codes/main-heating-e40/) - Central heating return sensor has a fault on Main Eco Compact boilers.
- [Main Heating E50 - Hot Water NTC Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e50/) - The domestic hot water temperature sensor has a fault on Main Heating boilers.
- [Main Heating E60 - Fan or Fan Wiring Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e60/) - On some older Main boilers, E60 indicates a fan or fan wiring fault.
- [Main Heating E83 - Communication Error](https://boilerandspares.co.uk/fault-codes/main-heating-e83/) - Fix Main Heating E83 communication errors with clear fault-code guidance, likely causes and parts help. Check the code and order spares.
- [Main Heating E109 - Pre-Circulation Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e109/) - The boiler has detected insufficient circulation during its pre-circulation check.
- [Main Heating E135 - Gas Supply Interruption](https://boilerandspares.co.uk/fault-codes/main-heating-e135/) - The gas supply to the boiler has been interrupted.
- [Main Heating E154 - Flow/Return Sensor Test Failure](https://boilerandspares.co.uk/fault-codes/main-heating-e154/) - Fix Main Heating E154 flow/return sensor test failure with fault-code guidance, likely causes and parts help. Check the code and order spares.
- [Main Heating E321 - Hot Water NTC Fault (Eco Compact)](https://boilerandspares.co.uk/fault-codes/main-heating-e321/) - On Main Eco Compact boilers, E321 indicates a hot water thermistor fault.
- [Main Heating E384 - False Flame Detected](https://boilerandspares.co.uk/fault-codes/main-heating-e384/) - Main Heating E384 fault code means a false flame is detected. See likely causes, repair guidance and parts options, then fix the issue.
- [Intergas F000 - Heat Exchanger Sensor Fault (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f000/) - On Intergas Xtreme and Xclusive boilers, F000 indicates a heat exchanger sensor defect requiring replacement.
- [Intergas F001 - Overtemperature During CH Demand (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f001/) - Fix Intergas F001 overtemperature faults on Xtreme and Xclusive boilers with clear CH demand checks, likely causes and parts advice. See fixes.
- [Intergas F004 - No Flame During Startup (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f004/) - On Intergas Xtreme/Xclusive, F004 indicates no flame was detected during the ignition sequence. Gas valve may be closed or condensate drain blocked.
- [Intergas F005 - Flame Loss During Operation (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f005/) - On Intergas Xtreme/Xclusive, F005 means the flame has been lost during normal operation. Possible condensate blockage or flue recirculation.
- [Intergas F006 - False Flame Signal (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f006/) - On Intergas Xtreme/Xclusive, F006 indicates a flame simulation error — a flame is being detected when the gas valve is closed.
- [Intergas F008 - Incorrect Fan Speed (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f008/) - On Intergas Xtreme/Xclusive, F008 indicates the fan is not running at the correct speed. Fan cable, fan motor, or burner controller may be faulty.
- [Intergas F018 - Flue or Air Supply Blocked (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f018/) - On Intergas Xtreme/Xclusive, F018 indicates the flue and/or air supply duct is blocked. Check for obstructions at the flue terminal.
- [Intergas F029 - Gas Valve Fault (Xtreme/Xclusive)](https://boilerandspares.co.uk/fault-codes/intergas-f029/) - Fix Intergas F029 gas valve faults on Xtreme and Xclusive boilers with clear causes, checks and parts advice. Identify the issue now.
- [Intergas 0.0 - Low System Pressure (Standard Range)](https://boilerandspares.co.uk/fault-codes/intergas-0-0/) - On standard Intergas HRE boilers, 0.0 indicates the system water pressure is too low to operate safely.
- [Intergas 1 - Temperature Too High (Standard Range)](https://boilerandspares.co.uk/fault-codes/intergas-1/) - Fix Intergas 1 temperature too high fault code with clear fault checks, likely causes and parts advice. Identify the issue and order spares.
- [Intergas 4 - No Flame Signal (Standard Range)](https://boilerandspares.co.uk/fault-codes/intergas-4/) - Fix Intergas 4 no flame signal faults with standard range guidance, likely causes and parts support. Check symptoms and order spares.
- [Intergas 8 - Incorrect Fan Speed (Standard Range)](https://boilerandspares.co.uk/fault-codes/intergas-8/) - Fix Intergas fault code 8 incorrect fan speed standard range with clear diagnosis steps and genuine Boiler Spares parts. Order the right fix.
- [Intergas E1 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/intergas-e1/) - See what Intergas E1 ignition failure means, common causes, and the parts to check so you can diagnose the fault faster. View the guide.
- [Intergas E3 - Flame Lost](https://boilerandspares.co.uk/fault-codes/intergas-e3/) - Fix Intergas E3 flame lost faults with likely causes, step-by-step checks and spare parts guidance. Identify the issue and order parts.
- [Intergas E4 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/intergas-e4/) - Get clear steps to identify and fix the Intergas E4 overheat protection fault code, with parts guidance and practical checks. See the fix.
- [Intergas E8 - Fan Fault](https://boilerandspares.co.uk/fault-codes/intergas-e8/) - Understand the Intergas E8 fan fault code, common causes and fixes, with clear fault advice from Boiler Spares. Check the symptoms now.
- [Intergas E12 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/intergas-e12/) - Understand the Intergas E12 pressure sensor fault, its common causes and fix options, then identify the right part to replace.
- [Intergas E15 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/intergas-e15/) - Understand the Intergas E15 gas valve fault, common causes and likely fixes. Use our guide to diagnose the issue and choose the right part.
- [Intergas E18 - PCB Fault](https://boilerandspares.co.uk/fault-codes/intergas-e18/) - Understand the Intergas E18 PCB fault, its common causes and likely fixes, with clear guidance to diagnose the issue and order the right part.
- [Intergas E19 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/intergas-e19/) - Understand the Intergas E19 DHW sensor fault, its likely causes and fixes, with clear steps to diagnose the issue and order the right spare.
- [Intergas E21 - Flow Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/intergas-e21/) - See what the Intergas E21 open circuit flow sensor code means, common causes and likely fixes, then check the fault against the right spare.
- [Intergas E22 - Return Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/intergas-e22/) - Fix Intergas E22 return sensor open circuit faults with clear code guidance, likely causes and parts help. Check the right spares next.
- [Intergas E23 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/intergas-e23/) - Fix Intergas E23 condensate blocked faults with clear causes, checks and parts guidance. Identify the issue fast and order the right spares.
- [Intergas E24 - Pump Fault](https://boilerandspares.co.uk/fault-codes/intergas-e24/) - Understand the Intergas E24 pump fault, common causes and fixes, with clear guidance to diagnose the issue and order the right spare part.
- [Intergas E25 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/intergas-e25/) - Understand the Intergas E25 diverter valve fault, common causes and repair options with clear guidance. Check the fault and order parts.
- [Intergas E26 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/intergas-e26/) - Fix Intergas E26 air pressure switch faults with clear checks, likely causes and parts advice. Identify the issue fast and order the right spares.
- [Intergas F002 - Flame Supervision](https://boilerandspares.co.uk/fault-codes/intergas-f002/) - Fix an Intergas F002 Flame Supervision fault with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order spares.
- [Intergas F003 - Overheat](https://boilerandspares.co.uk/fault-codes/intergas-f003/) - Understand the Intergas F003 overheat fault code, its common causes and likely fixes. Diagnose the issue faster and see the next checks.
- [Intergas F007 - Ionisation Fault](https://boilerandspares.co.uk/fault-codes/intergas-f007/) - Understand the Intergas F007 ionisation fault, common causes and fix options with clear guidance. Check the fault and order parts.
- [Intergas F009 - Gas Valve](https://boilerandspares.co.uk/fault-codes/intergas-f009/) - Fix an Intergas F009 gas valve fault with clear code guidance, likely causes and parts support from Boiler Spares. Check the remedy now.
- [Intergas F010 - Low Pressure](https://boilerandspares.co.uk/fault-codes/intergas-f010/) - Fix Intergas F010 low pressure faults with clear causes, checks and parts advice from Boiler Spares. Identify the issue and order the right part.
- [Intergas F011 - Fan Speed](https://boilerandspares.co.uk/fault-codes/intergas-f011/) - Fix an Intergas F011 fan speed fault with clear fault code guidance and matching boiler spares. Check symptoms, identify parts and order.
- [Intergas F012 - NTC Fault](https://boilerandspares.co.uk/fault-codes/intergas-f012/) - See what the Intergas F012 NTC fault means, common causes and likely fixes, with clear guidance to help identify the issue and order parts.
- [Intergas F013 - PCB Error](https://boilerandspares.co.uk/fault-codes/intergas-f013/) - Understand Intergas F013 PCB errors fast with clear causes, repair steps and parts advice from Boiler Spares. Check the fix.
- [Intergas F015 - Condensate](https://boilerandspares.co.uk/fault-codes/intergas-f015/) - Fix Intergas F015 condensate fault codes with clear fault checks, likely causes and parts guidance. Identify the issue and order spares.
- [Intergas F020 - Pump](https://boilerandspares.co.uk/fault-codes/intergas-f020/) - Fix an Intergas F020 pump fault with clear causes, checks and part guidance from Boiler Spares. Identify the issue and order the right part.
- [Main Heating E10 - DHW NTC Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e10/) - Fix the Main Heating E10 DHW NTC fault with clear diagnosis steps, likely causes and part guidance. Check the guide and order spares.
- [Main Heating E11 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e11/) - Fix the Main Heating E11 fault code with clear return NTC fault checks, likely causes and parts guidance. Identify the issue and order spares.
- [Main Heating E12 - Flow NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/main-heating-e12/) - Fix the Main Heating E12 fault code for a flow NTC short circuit with clear checks, likely causes and the right spare parts. Diagnose it now.
- [Main Heating E13 - Return NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/main-heating-e13/) - Fix the Main Heating E13 fault code for a return NTC short circuit with clear checks and parts guidance. Identify the cause and order spares.
- [Main Heating E14 - DHW NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/main-heating-e14/) - Fix the Main Heating E14 fault code for a DHW NTC short circuit with clear checks, likely causes and parts advice. Diagnose the issue now.
- [Main Heating E15 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/main-heating-e15/) - Fix Main Heating E15 diverter valve faults with clear checks, likely causes and parts advice. Identify the issue fast and order spares.
- [Ariston 502 - Flame Detected With Gas Valve Closed](https://boilerandspares.co.uk/fault-codes/ariston-502/) - The boiler's ionisation circuit is detecting a flame when the gas valve should be completely closed. A serious safety fault.
- [Ariston 101 - Overheat — Safety Thermostat Triggered](https://boilerandspares.co.uk/fault-codes/ariston-101/) - The boiler has overheated and the safety thermostat has shut it down. Usually caused by poor water circulation, low pressure, or a failing pump.
- [Ariston 108 - Insufficient Water — Refill Required](https://boilerandspares.co.uk/fault-codes/ariston-108/) - On Ariston combi boilers, code 108 indicates the system has insufficient water and needs to be repressurised.
- [Ariston 103 - Insufficient Water Circulation](https://boilerandspares.co.uk/fault-codes/ariston-103/) - The boiler is not detecting adequate water circulation through the primary heating circuit. Usually caused by an airlock, closed valves, or failing pump.
- [Ariston 110 - CH Flow Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/ariston-110/) - The central heating flow temperature sensor (probe) has an open circuit or short circuit fault.
- [Ariston 112 - CH Return Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/ariston-112/) - The central heating return temperature sensor has an open circuit or short circuit fault.
- [Ariston 301 - EEPROM Error — PCB Fault](https://boilerandspares.co.uk/fault-codes/ariston-301/) - There is an EEPROM (memory chip) fault on the main PCB. The boiler cannot read or write its configuration data.
- [Ariston 304 - Too Many Resets — 5 in 15 Minutes](https://boilerandspares.co.uk/fault-codes/ariston-304/) - The boiler has been reset 5 or more times within 15 minutes and has entered a protective lockout.
- [Ariston 604 - Insufficient Fan Speed](https://boilerandspares.co.uk/fault-codes/ariston-604/) - The boiler fan is not reaching the required speed for safe combustion — preventing ignition.
- [Ariston 610 - Thermal Fuse Open](https://boilerandspares.co.uk/fault-codes/ariston-610/) - The thermal fuse (a one-time safety device) has activated due to extreme overheating. Once blown, it cannot be reset — it must be replaced.
- [Ariston 5P1 - First Ignition Failed (Warning)](https://boilerandspares.co.uk/fault-codes/ariston-5p1/) - The first ignition attempt failed — the boiler will try again. This is a warning (non-lockout) code.
- [Ariston 5P2 - Second Ignition Failed (Warning)](https://boilerandspares.co.uk/fault-codes/ariston-5p2/) - The second ignition attempt has also failed. The boiler may escalate to a 501 lockout.
- [Ariston 102 - Pressure Sensor Error (E-Combi Evo)](https://boilerandspares.co.uk/fault-codes/ariston-102/) - Fix Ariston 102 pressure sensor errors on E-Combi Evo boilers with clear fault code guidance and parts advice. Check the remedy.
- [Ariston 109 - System Pressure Too High (Clas Net One)](https://boilerandspares.co.uk/fault-codes/ariston-109/) - Fix Ariston 109 system pressure too high on a Clas Net One with clear fault code checks and parts guidance. View the steps and identify spares.
- [Ariston 612 - Fan Speed Incorrect Measurement](https://boilerandspares.co.uk/fault-codes/ariston-612/) - The fan speed sensor is giving an incorrect reading — fan speed cannot be confirmed as safe for operation.
- [Ariston 303 - Main PCB Error](https://boilerandspares.co.uk/fault-codes/ariston-303/) - The main Printed Circuit Board has detected an internal error.
- [Ariston 302 - Communication Error — PCB](https://boilerandspares.co.uk/fault-codes/ariston-302/) - Fix Ariston 302 communication errors with the right PCB fault guidance from Boiler Spares. Check causes, parts advice and next repair steps.
- [Ariston 504 - Flame Lift](https://boilerandspares.co.uk/fault-codes/ariston-504/) - The boiler has detected 'flame lift' — the flame has lifted away from the burner surface, causing unstable combustion.
- [Intergas E2 - Ignition Failure / Lockout](https://boilerandspares.co.uk/fault-codes/intergas-e2/) - The most common Intergas fault code. The boiler has failed to ignite or has lost its flame. On Intergas boilers, E2 is the primary ignition lockout code.
- [Intergas E5 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/intergas-e5/) - The boiler's overtemperature protection has activated. On Intergas boilers this typically means the heat exchanger has reached an unsafe temperature.
- [Intergas E6 - Fan Fault / Air Pressure Switch](https://boilerandspares.co.uk/fault-codes/intergas-e6/) - The fan is not confirming correct operation via the air pressure switch before ignition is allowed.
- [Intergas E7 - Water Pressure Too Low](https://boilerandspares.co.uk/fault-codes/intergas-e7/) - System water pressure is below the safe operating minimum for the boiler.
- [Intergas E9 - Flow/Return Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/intergas-e9/) - A flow or return NTC temperature sensor has failed or has a wiring fault on Intergas boilers.
- [Intergas E10 - False Flame Detected](https://boilerandspares.co.uk/fault-codes/intergas-e10/) - Fix Intergas E10 false flame detected faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Ariston 104 - Insufficient Circulation / Pump Fault](https://boilerandspares.co.uk/fault-codes/ariston-104/) - Fix Ariston 104 insufficient circulation pump faults with clear checks, likely causes and spare part guidance. Identify the issue now.
- [Ariston 105 - Insufficient Circulation on DHW Circuit](https://boilerandspares.co.uk/fault-codes/ariston-105/) - Fix Ariston 105 insufficient circulation on the DHW circuit with clear fault code guidance, likely causes and parts advice. Check the fix.
- [Ariston 106 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/ariston-106/) - Fix Ariston 106 low water pressure fault code with clear checks, likely causes and spare parts guidance. Identify the fault and order parts.
- [Ariston 107 - Low Water Pressure with No Reset](https://boilerandspares.co.uk/fault-codes/ariston-107/) - Fix Ariston 107 low water pressure faults without a reset. See likely causes, practical checks and the right spares, then diagnose the issue.
- [Ariston 201 - Flow Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/ariston-201/) - Understand Ariston 201 flow temperature sensor fault code, common causes and fixes, with boiler spares guidance. Check symptoms and next steps.
- [Ariston 202 - DHW Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/ariston-202/) - Fix an Ariston 202 DHW temperature sensor fault with clear checks, likely causes and parts guidance. Identify the issue and order the right spares.
- [Ariston 203 - Return Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/ariston-203/) - Fix an Ariston 203 return temperature sensor fault with clear causes, checks and parts advice from Boiler Spares. Identify the issue now.
- [Ariston 305 - PCB / EEPROM Error](https://boilerandspares.co.uk/fault-codes/ariston-305/) - Fix Ariston 305 PCB/EEPROM faults with clear error code causes, checks and repair advice from Boiler Spares. View the guide.
- [Ariston 306 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/ariston-306/) - Fix the Ariston 306 air pressure switch fault code with clear checks, likely causes and parts advice. See the fault steps and order spares.
- [Ariston 601 - Fan Fault](https://boilerandspares.co.uk/fault-codes/ariston-601/) - Understand the Ariston 601 fan fault code, common causes and checks, with clear guidance to diagnose the issue and order the right part.
- [Ariston 607 - Gas Valve Relay Fault](https://boilerandspares.co.uk/fault-codes/ariston-607/) - Fix an Ariston 607 gas valve relay fault with clear causes, checks and parts advice from Boiler Spares. See the fault and order the right spares.
- [Ariston 111 - Pump Fault](https://boilerandspares.co.uk/fault-codes/ariston-111/) - Understand Ariston 111 pump faults, common causes and practical fixes. Use our clear guide to diagnose the issue and check the next step.
- [Ariston 114 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/ariston-114/) - Understand Ariston 114 diverter valve fault codes, spot likely causes and check compatible boiler spares. See the fault guide now.
- [Ariston 115 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/ariston-115/) - See what causes the Ariston 115 condensate blocked fault code, how to spot the issue, and what to check next before calling an engineer.
- [Ariston 116 - PCB Communication Error](https://boilerandspares.co.uk/fault-codes/ariston-116/) - Fix Ariston 116 PCB communication errors with clear fault code checks, likely causes and parts advice. Identify the issue and order spares.
- [Ariston 117 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/ariston-117/) - Understand Ariston 117 eBUS fault code, its likely causes and practical fixes, with clear guidance to troubleshoot or order the right spare part.
- [Ariston 118 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/ariston-118/) - Fix Ariston 118 fault code with clear checks for flame detected after shutdown, plus likely causes and parts guidance. See the steps.
- [Ariston 119 - Combustion Quality Fault](https://boilerandspares.co.uk/fault-codes/ariston-119/) - Fix Ariston 119 combustion quality fault code with clear causes, checks and parts guidance from Boiler Spares. View the fault code page.
- [Ariston 120 - Flow/Return Sensors Reversed](https://boilerandspares.co.uk/fault-codes/ariston-120/) - Understand the Ariston 120 flow/return sensors reversed fault code, its likely causes and fixes, with Boiler Spares guidance. Check symptoms.
- [Ariston 121 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/ariston-121/) - Understand Ariston 121 mains voltage fault code fast with clear causes, checks and fix options. Identify the fault and order the right spares.
- [Ariston 122 - Phase/Neutral Reversed](https://boilerandspares.co.uk/fault-codes/ariston-122/) - Fix Ariston 122 phase neutral reversed faults with clear causes, checks and parts advice from Boiler Spares. See the code and fix.
- [Ariston 123 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/ariston-123/) - Fix Ariston 123 Frost Protection Active fault codes with clear causes, part guidance and repair steps. Check the fault and order spares.
- [Ariston 124 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/ariston-124/) - Understand Ariston 124 EEPROM fault codes, likely causes and practical fixes. Use our clear guide to identify the issue and check next steps.
- [Ariston 125 - Coding Plug Fault](https://boilerandspares.co.uk/fault-codes/ariston-125/) - Fix the Ariston 125 coding plug fault with clear fault details, likely causes and compatible spare parts. Check the right part now.
- [Ariston 126 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/ariston-126/) - Fix Ariston 126 outdoor sensor fault codes with clear causes, testing steps and parts guidance. Check the fault and choose the right fix.
- [Ariston 127 - Fan Speed Error](https://boilerandspares.co.uk/fault-codes/ariston-127/) - Understand Ariston 127 fan speed fault codes fast with clear causes, checks and parts guidance. Fix the issue sooner with Boiler Spares.
- [Ariston 128 - Gas Valve Relay Fault](https://boilerandspares.co.uk/fault-codes/ariston-128/) - See what the Ariston 128 gas valve relay fault code means, common causes and likely fixes, then check compatible Boiler Spares parts.
- [Vokera A01 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/vokera-a01/) - The boiler has failed to ignite — the flame was not sensed during the ignition sequence. The most common Vokera fault code.
- [Vokera A02 - Limit Thermostat Fault](https://boilerandspares.co.uk/fault-codes/vokera-a02/) - The safety limit thermostat has activated or has a fault. This can indicate the boiler is overheating or the thermostat itself has failed.
- [Vokera A03 - Fan Fault](https://boilerandspares.co.uk/fault-codes/vokera-a03/) - The boiler fan is not operating correctly — it may not be starting, running too slowly, or the speed signal is faulty.
- [Vokera A04 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/vokera-a04/) - The system water pressure is insufficient for safe operation. The most common easily-fixable Vokera fault.
- [Vokera A06 - DHW Thermistor Fault](https://boilerandspares.co.uk/fault-codes/vokera-a06/) - The domestic hot water temperature sensor has a fault — open circuit, short circuit, or damaged wiring.
- [Vokera A07 - Primary Flow Thermistor Fault](https://boilerandspares.co.uk/fault-codes/vokera-a07/) - Fix Vokera A07 primary flow thermistor faults with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order the right part.
- [Vokera A08 - Return Thermistor Fault](https://boilerandspares.co.uk/fault-codes/vokera-a08/) - The return temperature sensor has a fault — the return water temperature is reading too high or the sensor has failed.
- [Vokera A09 - Flue Thermistor Fault](https://boilerandspares.co.uk/fault-codes/vokera-a09/) - The flue gas temperature sensor has a fault, or there may be a flue thermostat counter issue.
- [Vokera A11 - False Flame Detected](https://boilerandspares.co.uk/fault-codes/vokera-a11/) - The boiler is detecting a flame signal when none should be present. A serious safety fault requiring immediate attention.
- [Vokera 01 - Failure to Ignite (Simple Display)](https://boilerandspares.co.uk/fault-codes/vokera-01/) - On Vokera boilers with simpler displays, code 01 indicates the boiler has failed to ignite.
- [Vokera 02 - Overheat (Simple Display)](https://boilerandspares.co.uk/fault-codes/vokera-02/) - Fix Vokera 02 overheat faults on Simple Display boilers with clear fault code guidance and parts support. Check the cause and next steps.
- [Vokera 03 - Fan/Flue Problem (Simple Display)](https://boilerandspares.co.uk/fault-codes/vokera-03/) - On Vokera boilers with simpler displays, code 03 indicates a problem with the fan or flue system.
- [Vokera 04 - Low Water Pressure (Simple Display)](https://boilerandspares.co.uk/fault-codes/vokera-04/) - On Vokera boilers with simpler displays, code 04 indicates insufficient water pressure.
- [Vokera E10 - Flame Lockout (Evolve)](https://boilerandspares.co.uk/fault-codes/vokera-e10/) - On Vokera Evolve boilers, E10 indicates a flame lockout — the boiler has failed to ignite or lost its flame.
- [Vokera E011 - Extraneous Flame (Evolve)](https://boilerandspares.co.uk/fault-codes/vokera-e011/) - On Vokera Evolve boilers, E011 indicates an extraneous (false) flame has been detected when the burner should be off.
- [Vokera E020 - Limit Thermostat / Overheat (Evolve)](https://boilerandspares.co.uk/fault-codes/vokera-e020/) - On Vokera Evolve boilers, E020 indicates the limit thermostat has been activated due to overheating.
- [Vokera E030 - Fan Fault (Evolve)](https://boilerandspares.co.uk/fault-codes/vokera-e030/) - On Vokera Evolve boilers, E030 indicates a fan fault.
- [Vokera E040 - Low Water Pressure (Evolve)](https://boilerandspares.co.uk/fault-codes/vokera-e040/) - On Vokera Evolve boilers, E040 indicates low system water pressure via the water transducer.
- [Vokera AL40 - Low Water Pressure (Mynute)](https://boilerandspares.co.uk/fault-codes/vokera-al40/) - Fix Vokera AL40 low water pressure faults on Mynute boilers with clear checks and likely causes. Identify the issue and order the right spares.
- [Vokera AL41 - Very Low Water Pressure (Mynute)](https://boilerandspares.co.uk/fault-codes/vokera-al41/) - On Vokera Mynute boilers, AL41 indicates critically low system water pressure.
- [Ariston 501 - No Flame Detected / Ignition Failure](https://boilerandspares.co.uk/fault-codes/ariston-501/) - Fix Ariston 501 no flame detected and ignition failure faults with clear checks, likely causes and spare parts advice. View the guide.
- [Vokera A05 - Fan Fault](https://boilerandspares.co.uk/fault-codes/vokera-a05/) - Understand the Vokera A05 fan fault, common causes and the right replacement parts with expert guidance. Check the fault code now.
- [Vokera A10 - Return NTC Fault](https://boilerandspares.co.uk/fault-codes/vokera-a10/) - Understand the Vokera A10 return NTC fault with clear causes, checks and parts guidance from Boiler Spares. Fix the issue faster.
- [Vokera A12 - DHW NTC Fault](https://boilerandspares.co.uk/fault-codes/vokera-a12/) - See what the Vokera A12 DHW NTC fault means, common causes and likely fixes, with clear parts guidance. Check the fault and order spares.
- [Vokera A13 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/vokera-a13/) - Fix a Vokera A13 low water pressure fault with clear causes, checks and part guidance from Boiler Spares. Identify the issue fast.
- [Vokera A14 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/vokera-a14/) - Understand the Vokera A14 fault code for rapid temperature rise, what causes it, and the parts you may need. Check the fault guide now.
- [Vokera A15 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/vokera-a15/) - Fix a Vokera A15 condensate blocked fault with clear checks, likely causes and spare parts guidance. Identify the issue and act fast.
- [Vokera A16 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/vokera-a16/) - See what the Vokera A16 gas valve fault means, common causes and the parts you may need to fix it. Check the fault and order spares.
- [Vokera A17 - PCB Fault](https://boilerandspares.co.uk/fault-codes/vokera-a17/) - Understand the Vokera A17 PCB fault, see the parts you may need, and order genuine boiler spares with fast UK delivery. Check compatibility.
- [Vokera A18 - Overheat Protection](https://boilerandspares.co.uk/fault-codes/vokera-a18/) - Fix a Vokera A18 overheat protection fault with clear checks, likely causes and spare part guidance. Identify the fault and order parts.
- [Vokera A19 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/vokera-a19/) - Understand Vokera A19 diverter valve fault codes with clear causes, fixes and parts guidance. Identify the fault fast and view spares.
- [Vokera A20 - Pump Fault](https://boilerandspares.co.uk/fault-codes/vokera-a20/) - Fix a Vokera A20 pump fault with clear causes, part guidance and compatible spares from Boiler Spares. Identify the issue and order parts.
- [Vokera 05 - Fan Fault](https://boilerandspares.co.uk/fault-codes/vokera-05/) - Fix a Vokera 05 fan fault with clear checks, likely causes and parts advice from Boiler Spares. Identify the issue and order the right part.
- [Vokera 06 - Air Pressure Switch](https://boilerandspares.co.uk/fault-codes/vokera-06/) - Get clear help with the Vokera 06 air pressure switch fault code, including likely causes and the right spare parts. Check the fix now.
- [Vokera 07 - Overheat](https://boilerandspares.co.uk/fault-codes/vokera-07/) - Fix a Vokera 07 overheat fault with clear fault code guidance, likely causes and spare parts help. Identify the issue and order parts.
- [Vokera 08 - NTC Fault](https://boilerandspares.co.uk/fault-codes/vokera-08/) - See what the Vokera 08 NTC fault code means, common causes and parts you may need, with clear guidance to identify the fault and fix it.
- [Vokera 09 - Gas Valve](https://boilerandspares.co.uk/fault-codes/vokera-09/) - See what the Vokera 09 gas valve fault code means, common causes and practical checks, with clear fixes before you call an engineer.
- [Vokera 10 - Low Pressure](https://boilerandspares.co.uk/fault-codes/vokera-10/) - Fix Vokera 10 low pressure fault code issues with clear boiler checks, common causes and spare parts advice. See the fault steps now.
- [Vokera 11 - Pump Fault](https://boilerandspares.co.uk/fault-codes/vokera-11/) - See what the Vokera 11 pump fault code means, common causes and practical fixes, with clear steps to diagnose the issue and order the right part.
- [Vokera 12 - Condensate](https://boilerandspares.co.uk/fault-codes/vokera-12/) - Understand Vokera 12 condensate fault codes, common causes and practical fixes. Identify the issue fast and check the right boiler spares.
- [Viessmann 62 - Pump Kickback Fault](https://boilerandspares.co.uk/fault-codes/viessmann-62/) - Understand Viessmann 62 pump kickback fault codes, common causes and practical fixes. Use our guide to identify the issue and order parts.
- [Viessmann 68 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/viessmann-68/) - See what Viessmann 68 means when frost protection is active, with clear fault guidance and parts support. Check the code and next steps.
- [Viessmann EA - Ignition Failure / No Flame Detected](https://boilerandspares.co.uk/fault-codes/viessmann-ea/) - On Viessmann Vitodens boilers, code EA (or E4 on some models) indicates the burner flame signal is too weak or missing after ignition attempt. Common in winter due to condensate…
- [Viessmann F4 EE - Frozen Condensate Pipe](https://boilerandspares.co.uk/fault-codes/viessmann-f4-ee/) - Viessmann's specific code for a frozen or blocked condensate pipe. The most common Vitodens winter fault.
- [Viessmann 0C - Flame After Shutdown (Vitodens 200)](https://boilerandspares.co.uk/fault-codes/viessmann-0c/) - On Vitodens 200-W boilers, code 0C indicates a flame signal was still present after the burner was commanded to shut down. Safety-critical fault.
- [Viessmann F5 - Gas Pressure Switch / No Gas Pressure](https://boilerandspares.co.uk/fault-codes/viessmann-f5/) - The gas pressure switch is showing no gas pressure, or there is an electrical connection fault at the pressure switch. Could mean the gas shut-off valve is closed.
- [Viessmann 0B - Fan Speed Error — Wind Conditions](https://boilerandspares.co.uk/fault-codes/viessmann-0b/) - On Vitodens 200 boilers, code 0B indicates the fan has not idled correctly after an auto-reset, possibly due to severe wind conditions in the flue system. On Vitodens 100-W, indicates…
- [Viessmann CE - Water Pressure Too Low (GB162)](https://boilerandspares.co.uk/fault-codes/viessmann-ce/) - Fix Viessmann GB162 CE low water pressure faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Viessmann C1 - Differential Air Pressure Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-c1/) - Fix a Viessmann C1 differential air pressure sensor fault with clear causes, checks and parts advice. See the steps and order the right spares.
- [Viessmann E4 - Burner Start Flame Signal Too Weak](https://boilerandspares.co.uk/fault-codes/viessmann-e4/) - Fix Viessmann E4 burner start flame signal faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Viessmann FC - Gas Valve Fault / Flue Blocked](https://boilerandspares.co.uk/fault-codes/viessmann-fc/) - On Viessmann boilers, code FC indicates either a gas valve fault, a faulty modulation valve control, or the flue system is blocked. Requires prompt professional attention.
- [Viessmann FE - EMC Interference / PCB Fault](https://boilerandspares.co.uk/fault-codes/viessmann-fe/) - Strong electromagnetic interference (EMC) nearby or a faulty main PCB is causing the burner to block or show errors.
- [Viessmann 30 - Boiler Water Temperature Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-30/) - The main boiler water temperature sensor (NTC) has short-circuited. On some Viessmann models the burner continues at an adjustable high limit; on others it is blocked.
- [Viessmann 38 - Boiler Water Temperature Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-38/) - The main boiler water temperature sensor cable has broken or become disconnected.
- [Viessmann A4 - Air Lock in Pump / Insufficient Flow (Vitodens 222-F)](https://boilerandspares.co.uk/fault-codes/viessmann-a4/) - On Vitodens 222-F boilers, code A4 indicates an air lock in the internal circulation pump or insufficient minimum flow rate. The venting program starts automatically.
- [Viessmann 0F - Boiler Service Required](https://boilerandspares.co.uk/fault-codes/viessmann-0f/) - Not a fault — this is a maintenance reminder indicating the boiler is due for its annual service.
- [Viessmann F2 - Burner Start Fault](https://boilerandspares.co.uk/fault-codes/viessmann-f2/) - Understand the Viessmann F2 burner start fault, its likely causes and fixes, then identify the right boiler spare parts to resolve it.
- [Viessmann F3 - Flame Signal Lost During Operation](https://boilerandspares.co.uk/fault-codes/viessmann-f3/) - Get the meaning of Viessmann F3 flame signal lost, common causes and likely fixes from boiler parts experts. Check the fault code guidance.
- [Viessmann A3 - Flue Gas Temperature Limiter](https://boilerandspares.co.uk/fault-codes/viessmann-a3/) - Fix the Viessmann A3 flue gas temperature limiter fault with clear fault-code guidance and compatible boiler spares. Check the details now.
- [Viessmann E0 - Safety Temperature Limiter Triggered](https://boilerandspares.co.uk/fault-codes/viessmann-e0/) - See why a Viessmann E0 safety temperature limiter trips, common causes, and practical checks to restore heating. Fix the fault now.
- [Viessmann E1 - Outdoor Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/viessmann-e1/) - Diagnose Viessmann E1 outdoor temperature sensor faults with clear causes, checks and spare part guidance. Identify the fix and order parts.
- [Viessmann B1 - Coding Plug Missing](https://boilerandspares.co.uk/fault-codes/viessmann-b1/) - Fix a Viessmann B1 coding plug missing fault code with clear fault guidance and parts support from Boiler Spares. Check the remedy.
- [Viessmann F6 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/viessmann-f6/) - Fix Viessmann F6 low water pressure faults with clear checks, likely causes and parts guidance. Diagnose the issue and order spares.
- [Viessmann 10 - DHW Outlet Temperature Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-10/) - Fix Viessmann 10 DHW outlet temperature sensor short circuit faults with clear causes, checks and parts advice. View the fault code guide.
- [Viessmann 18 - Pump Blocked or Not Running](https://boilerandspares.co.uk/fault-codes/viessmann-18/) - Fix Viessmann 18 fault code fast with checks for a blocked or failed pump, likely causes and parts guidance. Identify the fault and order spares.
- [Viessmann 40 - Internal Bus Communication Fault](https://boilerandspares.co.uk/fault-codes/viessmann-40/) - Fix a Viessmann 40 internal bus communication fault with clear fault code advice, likely causes and parts guidance. Check the fix now.
- [Viessmann 50 - No Flame Detected](https://boilerandspares.co.uk/fault-codes/viessmann-50/) - Fix Viessmann 50 no flame detected faults with clear checks, likely causes and parts advice from Boiler Spares. Diagnose the issue now.
- [Viessmann 51 - Flame Signal Present Without Gas Release](https://boilerandspares.co.uk/fault-codes/viessmann-51/) - Understand Viessmann 51 fault code, why a flame signal shows without gas, and the likely checks needed. See fault causes and fixes.
- [Viessmann 5C - Outdoor Temperature Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-5c/) - Fix a Viessmann 5C outdoor temperature sensor open circuit fault with clear cause checks and parts guidance. See the repair steps.
- [Viessmann 92 - Air/Gas Mixture Setting Error](https://boilerandspares.co.uk/fault-codes/viessmann-92/) - Fix Viessmann 92 air/gas mixture setting errors with clear fault code guidance, likely causes and parts advice. Check the fault now.
- [Viessmann A9 - Condensate Drain Blocked](https://boilerandspares.co.uk/fault-codes/viessmann-a9/) - Fix Viessmann A9 condensate drain blocked faults with clear causes, checks and parts guidance from Boiler Spares. See the fault code steps.
- [Viessmann A6 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/viessmann-a6/) - Fix Viessmann A6 low gas pressure faults with clear causes, checks and part guidance from Boiler Spares. Identify the issue and order spares.
- [Viessmann 02 - DHW Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-02/) - Fix Viessmann 02 DHW sensor short circuit faults with clear causes, checks and parts guidance. Identify the issue fast and order spares.
- [Viessmann 04 - Flow Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-04/) - Fix Viessmann 04 flow sensor short circuit faults with clear checks, likely causes and spare part guidance. See the fault code steps.
- [Viessmann 05 - Return Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-05/) - Fix a Viessmann 05 return sensor short circuit fault with clear causes, checks and parts advice. Identify the issue and order the right spares.
- [Viessmann 06 - Flow Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-06/) - Understand the Viessmann 06 Flow Sensor Open Circuit fault, its likely causes and fixes, then check the right Boiler Spares part.
- [Viessmann 07 - Return Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-07/) - Fix Viessmann 07 return sensor open circuit faults with clear causes, checks and spare part guidance. Identify the issue and order parts.
- [Viessmann 08 - DHW Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-08/) - See what the Viessmann 08 DHW sensor open circuit fault code means, likely causes and fixes, with parts guidance from Boiler Spares. Check yours.
- [Viessmann 09 - Combustion Chamber Sensor Fault](https://boilerandspares.co.uk/fault-codes/viessmann-09/) - Fix Viessmann 09 combustion chamber sensor faults with clear causes, likely parts and practical checks. See the fault guide and next steps.
- [Viessmann 0D - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/viessmann-0d/) - Understand the Viessmann 0D gas valve fault, its likely causes and fixes, with clear guidance to identify the issue and check parts.
- [Viessmann 0E - PCB Fault](https://boilerandspares.co.uk/fault-codes/viessmann-0e/) - Understand Viessmann 0E PCB fault codes with clear causes, checks and repair advice from Boiler Spares. Identify the issue and order parts.
- [Viessmann 14 - Pump Blocked](https://boilerandspares.co.uk/fault-codes/viessmann-14/) - Fix a Viessmann 14 pump blocked fault with clear checks, likely causes and parts guidance from Boiler Spares. See the fault code steps.
- [Viessmann 15 - Pump Running Dry](https://boilerandspares.co.uk/fault-codes/viessmann-15/) - Understand Viessmann 15 fault code for a pump running dry, with clear causes and practical fixes. Check the fault details and next steps.
- [Viessmann 20 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/viessmann-20/) - Understand the Viessmann 20 diverter valve fault code, its likely causes and fixes, then check compatible Boiler Spares parts.
- [Viessmann 44 - Flue Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-44/) - See what the Viessmann 44 flue sensor short circuit fault code means, common causes and likely fixes. Check the fault and order the right spare.
- [Viessmann 45 - Flue Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-45/) - Fix the Viessmann 45 flue sensor open circuit fault with clear cause checks, parts guidance and repair steps. See the fault code now.
- [Viessmann 48 - eBUS Communication Fault](https://boilerandspares.co.uk/fault-codes/viessmann-48/) - Fix Viessmann 48 eBUS communication fault code with clear causes, checks and parts guidance from Boiler Spares. View the fault code now.
- [Viessmann 54 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/viessmann-54/) - Fix Viessmann 54 condensate blocked fault codes with clear checks, common causes and part guidance. Identify the issue and order spares.
- [Viessmann 60 - Fan Speed Fault](https://boilerandspares.co.uk/fault-codes/viessmann-60/) - Understand Viessmann 60 fan speed fault codes, common causes and likely fixes. Use our clear guide to diagnose the issue and check parts.
- [Viessmann 70 - Outdoor Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-70/) - Fix Viessmann 70 outdoor sensor open circuit faults with clear checks, likely causes and part guidance. Identify the issue and order spares.
- [Viessmann 71 - Outdoor Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/viessmann-71/) - Understand Viessmann 71 outdoor sensor short circuit code, common causes and likely fixes. Check symptoms and order the right spare part.
- [Viessmann 73 - Water Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/viessmann-73/) - Fix Viessmann 73 water pressure sensor fault codes with clear checks, likely causes and parts help from Boiler Spares. Identify the fault fast.
- [Viessmann 77 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/viessmann-77/) - Fix Viessmann 77 frost protection active fault code with clear causes, checks and spare part guidance. Identify the fault and order parts.
- [Viessmann 90 - Coding Plug Fault](https://boilerandspares.co.uk/fault-codes/viessmann-90/) - Fix a Viessmann 90 coding plug fault code with clear causes, checks and parts guidance from Boiler Spares. See the fault code steps.
- [Viessmann 91 - Appliance Variant Error](https://boilerandspares.co.uk/fault-codes/viessmann-91/) - Fix Viessmann 91 appliance variant error code with clear fault checks and parts guidance from Boiler Spares. Identify the cause and order spares.
- [Viessmann 95 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/viessmann-95/) - Understand Viessmann 95 fault code, why flame is detected after shutdown, and the likely fixes. Check symptoms and troubleshooting steps.
- [Viessmann 0A - Flow Temperature Sensor Fault](https://boilerandspares.co.uk/fault-codes/viessmann-0a/) - Fix the Viessmann 0A flow temperature sensor fault with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Viessmann 11 - Fan Speed Too Low](https://boilerandspares.co.uk/fault-codes/viessmann-11/) - See what Viessmann 11 means when fan speed is too low, common causes, and the parts you may need to fix it. Check the fault code guide.
- [Viessmann 12 - Fan Speed Too High](https://boilerandspares.co.uk/fault-codes/viessmann-12/) - Fix Viessmann 12 fault code fan speed too high with clear checks, likely causes and parts guidance. Identify the fault and order spares.
- [Viessmann 16 - Flame Instability](https://boilerandspares.co.uk/fault-codes/viessmann-16/) - Fix Viessmann 16 fault code flame instability with clear checks, likely causes and spare parts guidance. Identify the fault and order parts.
- [Viessmann 19 - Ignition Lead Fault](https://boilerandspares.co.uk/fault-codes/viessmann-19/) - Understand Viessmann 19 ignition lead faults with clear causes, checks and fixes from Boiler Spares. Identify the issue and order the right part.
- [Viessmann 22 - Three-Way Valve Stuck](https://boilerandspares.co.uk/fault-codes/viessmann-22/) - Fix a Viessmann 22 three-way valve stuck fault code with clear fault checks, likely causes and parts advice. Identify the issue and order spares.
- [Viessmann 24 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/viessmann-24/) - Rapid temperature rise fault on a Viessmann 24 boiler explained, with likely causes and part guidance to help identify the issue and order spares.
- [Viessmann 25 - Flow/Return Differential](https://boilerandspares.co.uk/fault-codes/viessmann-25/) - See what the Viessmann 25 flow/return differential fault code means, its likely causes and fixes, then check the right boiler spares.
- [Viessmann 32 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/viessmann-32/) - See what the Viessmann 32 low gas pressure fault code means, common causes and practical fixes to diagnose the issue. View the guide.
- [Viessmann 34 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/viessmann-34/) - Understand Viessmann 34 mains voltage fault codes with clear causes, checks and parts advice from Boiler Spares. See the fix.
- [Viessmann 36 - Phase/Neutral Reversed](https://boilerandspares.co.uk/fault-codes/viessmann-36/) - Fix a Viessmann 36 phase/neutral reversed fault with clear checks, likely causes and parts guidance. See the fault code steps.
- [Viessmann 42 - Coding Error](https://boilerandspares.co.uk/fault-codes/viessmann-42/) - Understand Viessmann 42 coding error fast with clear causes, checks and fixes from Boiler Spares. Identify the fault and order parts.
- [Viessmann 56 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/viessmann-56/) - Understand the Viessmann 56 EEPROM error code, its likely causes and practical fixes. Check the fault and order the right spares.
- [Viessmann 58 - Combustion Quality](https://boilerandspares.co.uk/fault-codes/viessmann-58/) - Fix Viessmann 58 combustion quality faults with clear causes, checks and parts guidance from Boiler Spares. See the code details now.
- [Ferroli A01 - Ignition Failure / No Flame](https://boilerandspares.co.uk/fault-codes/ferroli-a01/) - The boiler has failed to ignite — no flame was detected after the ignition sequence. This is the most common Ferroli fault code.
- [Ferroli F37 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/ferroli-f37/) - The system water pressure has dropped below the minimum required level.
- [Ferroli F05 - Air Pressure Switch Error](https://boilerandspares.co.uk/fault-codes/ferroli-f05/) - The air pressure switch is not registering correctly — this switch confirms the fan has reached the correct speed before ignition is allowed to proceed.
- [Ferroli D1 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/ferroli-d1/) - The diverter valve (which switches water flow between heating and hot water) appears to not be operating correctly.
- [Ferroli A02 - Flame Loss During Operation](https://boilerandspares.co.uk/fault-codes/ferroli-a02/) - Fix Ferroli A02 flame loss faults during operation with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Ferroli A03 - Safety Thermostat Lockout](https://boilerandspares.co.uk/fault-codes/ferroli-a03/) - The boiler safety thermostat has triggered due to overheating.
- [Ferroli A07 - Fan Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a07/) - The fan is not operating at the required speed or has stopped.
- [Ferroli A13 - Flow NTC Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a13/) - The flow temperature sensor has failed or has a wiring fault.
- [Ferroli A14 - Return NTC Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a14/) - The return temperature sensor has failed or has a wiring fault.
- [Ferroli F01 - Low Water Pressure Warning](https://boilerandspares.co.uk/fault-codes/ferroli-f01/) - Fix Ferroli F01 low water pressure warnings with clear fault code guidance, likely causes and parts help. Check the fix and order spares.
- [Ferroli A27 - PCB Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a27/) - The main PCB has detected an internal fault.
- [Ferroli A04 - False Ionisation / Flame Detected Without Demand](https://boilerandspares.co.uk/fault-codes/ferroli-a04/) - The boiler's ionisation circuit is detecting a flame when none should be present. A serious safety fault.
- [Ferroli A05 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/ferroli-a05/) - The safety thermostat has detected excessively high temperatures and shut the boiler down.
- [Ferroli A06 - Overheat Lockout — Secondary](https://boilerandspares.co.uk/fault-codes/ferroli-a06/) - A secondary overheat safety device has activated.
- [Ferroli A08 - Fan Overspeed](https://boilerandspares.co.uk/fault-codes/ferroli-a08/) - The fan is running above its rated maximum speed.
- [Ferroli A09 - Fan Not Responding to Start Command](https://boilerandspares.co.uk/fault-codes/ferroli-a09/) - The fan has not started within the required time after the PCB sent the start signal.
- [Ferroli A15 - DHW Outlet Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a15/) - The domestic hot water outlet temperature sensor has failed or has a wiring issue.
- [Ferroli A16 - Gas Valve Lockout — Failed to Close](https://boilerandspares.co.uk/fault-codes/ferroli-a16/) - The gas valve has failed to close correctly after the burner should have stopped. Safety-critical.
- [Ferroli F03 - Low Water Pressure (Warning)](https://boilerandspares.co.uk/fault-codes/ferroli-f03/) - System pressure is approaching the minimum — a warning before lockout occurs.
- [Ferroli F10 - Flue Temperature Too High](https://boilerandspares.co.uk/fault-codes/ferroli-f10/) - The flue gas temperature sensor has detected temperatures above safe limits.
- [Ferroli F28 - Flame Loss (Condensate Related)](https://boilerandspares.co.uk/fault-codes/ferroli-f28/) - Flame loss associated with a blocked or frozen condensate pipe — Ferroli uses F28 specifically for condensate-related ignition failures on some newer models.
- [Ferroli A19 - PCB Fault — Communication Error](https://boilerandspares.co.uk/fault-codes/ferroli-a19/) - Fix Ferroli A19 PCB communication errors with clear fault code guidance, likely causes and parts advice. Check symptoms and order spares.
- [Ferroli A20 - Condensate Siphon Blocked](https://boilerandspares.co.uk/fault-codes/ferroli-a20/) - The internal condensate siphon is blocked with scale, debris, or ice.
- [Ferroli F07 - High Flue Gas Temperature](https://boilerandspares.co.uk/fault-codes/ferroli-f07/) - The flue gas probe (exchanger probe) has detected an excessively high temperature for more than 2 minutes. Indicates a heat exchanger blockage or circulation problem.
- [Ferroli F08 - Overtemperature Protection — Flow Sensor](https://boilerandspares.co.uk/fault-codes/ferroli-f08/) - Fix the Ferroli F08 overtemperature protection flow sensor fault with clear checks, likely causes and parts advice. Diagnose the issue now.
- [Ferroli F09 - Overtemperature Protection — Return Sensor](https://boilerandspares.co.uk/fault-codes/ferroli-f09/) - On Ferroli Bluehelix Tech boilers, F09 indicates the overtemperature protection has activated based on the return sensor — no water circulation or air in the system.
- [Ferroli F11 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f11/) - On Ferroli boilers, F11 indicates the return temperature sensor has a wiring fault (shorted or disconnected) or the sensor itself has failed.
- [Ferroli F12 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f12/) - The domestic hot water temperature sensor has a wiring fault (shorted or disconnected) or has failed. On Ferroli Bluehelix Tech and other combi models.
- [Ferroli F13 - Flue Probe Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f13/) - On Ferroli boilers, F13 indicates the flue gas probe has a wiring fault (shorted or disconnected) or has failed.
- [Ferroli F34 - Low Supply Voltage](https://boilerandspares.co.uk/fault-codes/ferroli-f34/) - On Ferroli boilers, F34 indicates the mains supply voltage has dropped below 170V — too low for safe operation.
- [Ferroli F35 - Incorrect Mains Frequency](https://boilerandspares.co.uk/fault-codes/ferroli-f35/) - On Ferroli boilers, F35 indicates an incorrect or irregular mains power frequency (should be 50Hz in the UK).
- [Ferroli F39 - External Temperature Probe Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f39/) - The optional external temperature probe (for weather compensation) has a wiring fault or has been disconnected after weather compensation mode was activated.
- [Ferroli F41 - Maximum Delta-T Protection Activated](https://boilerandspares.co.uk/fault-codes/ferroli-f41/) - On Ferroli Bluehelix Tech boilers, F41 indicates the maximum allowable temperature difference between flow and return has been exceeded, triggering protection.
- [Ferroli F42 - Sensor Control Protection Activated](https://boilerandspares.co.uk/fault-codes/ferroli-f42/) - On Ferroli Bluehelix Tech, F42 indicates the sensor control protection has activated due to heating or return sensor damage or disconnection.
- [Ferroli F43 - Heat Exchanger Protection — No Circulation](https://boilerandspares.co.uk/fault-codes/ferroli-f43/) - Fix the Ferroli F43 no circulation fault with clear heat exchanger checks, likely causes and parts guidance. Identify the issue fast.
- [Ferroli A62 - No Communication Between PCB and Gas Valve](https://boilerandspares.co.uk/fault-codes/ferroli-a62/) - On Ferroli boilers, A62 indicates there is no communication between the main PCB and the electronic gas valve. The PCB may not be connected to the valve or the valve…
- [Ferroli A64 - Maximum Consecutive Resets Exceeded](https://boilerandspares.co.uk/fault-codes/ferroli-a64/) - On Ferroli Bluehelix Tech boilers, A64 means the maximum number of consecutive resets has been reached. The boiler will not restart until the underlying fault is resolved.
- [Ferroli F56 - Calibration Error / Incomplete Calibration](https://boilerandspares.co.uk/fault-codes/ferroli-f56/) - On Ferroli Bluehelix Tech boilers, F56 indicates the auto-calibration procedure did not complete correctly, or there are incorrect parameters or a damaged electrode.
- [Ferroli A61 - PCB AGC01 Internal Error](https://boilerandspares.co.uk/fault-codes/ferroli-a61/) - Fix the Ferroli A61 PCB AGC01 internal error with clear fault code guidance and parts support from Boiler Spares. Check symptoms and options.
- [Ferroli F14 - Flow Sensor 2 / Fan Problem Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f14/) - On some Ferroli models, F14 indicates either a secondary delivery sensor fault (DOMIcondens) or a fan problem with interrupted tachometric signal (Modena HE System/Combi).
- [Ferroli F52 - Controller Internal Error](https://boilerandspares.co.uk/fault-codes/ferroli-f52/) - On Ferroli Modena HE combi boilers, F52 indicates the controller has an internal error.
- [Ferroli F15 - Supply Voltage Low (Modena HE)](https://boilerandspares.co.uk/fault-codes/ferroli-f15/) - On Ferroli Modena HE combi boilers, F15 indicates the supply voltage has dropped below 170V.
- [Ferroli A10 - Flow NTC Open Circuit](https://boilerandspares.co.uk/fault-codes/ferroli-a10/) - Fix Ferroli A10 flow NTC open circuit faults with clear checks, likely causes and parts guidance. Identify the issue fast and order spares.
- [Ferroli A11 - Return NTC Open Circuit](https://boilerandspares.co.uk/fault-codes/ferroli-a11/) - Fix a Ferroli A11 return NTC open circuit fault with clear causes, checks and part guidance from Boiler Spares. Identify the fault fast.
- [Ferroli A12 - DHW NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/ferroli-a12/) - Fix the Ferroli A12 DHW NTC short circuit fault with clear fault code guidance, likely causes and parts advice. Identify the issue fast.
- [Ferroli A17 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a17/) - Understand the Ferroli A17 gas valve fault, common causes and practical checks. Use our guide to identify the issue and choose the right fix.
- [Ferroli A18 - PCB Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a18/) - Understand Ferroli A18 PCB fault codes with clear causes, checks and parts guidance from Boiler Spares. Identify the fault and order the right part.
- [Ferroli A21 - Flue Temperature Too High](https://boilerandspares.co.uk/fault-codes/ferroli-a21/) - Fix Ferroli A21 flue temperature faults with clear checks, likely causes and parts guidance. Identify the issue fast and order the right spares.
- [Ferroli A22 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/ferroli-a22/) - See what the Ferroli A22 low gas pressure fault code means, common causes and repair advice to diagnose the issue and order the right boiler spares.
- [Ferroli A23 - Pump Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a23/) - Understand the Ferroli A23 pump fault, common causes and fixes, with clear guidance from Boiler Spares. Check the fault and order parts.
- [Ferroli A24 - Pump Over-Speed](https://boilerandspares.co.uk/fault-codes/ferroli-a24/) - Fix Ferroli A24 pump over-speed faults with clear code meaning, likely causes and parts guidance. Check the fault and order spares.
- [Ferroli A25 - Three-Way Valve Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a25/) - Fix Ferroli A25 three-way valve faults with clear checks, likely causes and spare part guidance. Identify the issue fast and view the next steps.
- [Ferroli A26 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/ferroli-a26/) - Fix a Ferroli A26 condensate blocked fault with clear causes, checks and part guidance from Boiler Spares. See the fault steps now.
- [Ferroli A28 - Flame Instability](https://boilerandspares.co.uk/fault-codes/ferroli-a28/) - See what the Ferroli A28 flame instability fault code means, common causes and practical checks to help identify the issue. View the guide.
- [Ferroli A29 - Fan Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a29/) - Get a clear explanation of the Ferroli A29 fan fault code, common causes and likely fixes from Boiler Spares. Check the fault and order parts.
- [Ferroli A30 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/ferroli-a30/) - See what the Ferroli A30 air pressure switch fault means, common causes and likely fixes, with clear guidance to diagnose the issue and order parts.
- [Ferroli A31 - Flow/Return Sensor Reversed](https://boilerandspares.co.uk/fault-codes/ferroli-a31/) - Fix Ferroli A31 flow/return sensor reversed faults with clear fault code guidance, likely causes and parts help. Check the remedy now.
- [Ferroli F02 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/ferroli-f02/) - Fix Ferroli F02 overheat lockout faults with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order spares.
- [Ferroli F04 - Ionisation Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f04/) - Fix the Ferroli F04 ionisation fault with clear causes, checks and parts advice from Boiler Spares. Identify the issue and order spares.
- [Ferroli F06 - Flue Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f06/) - Understand the Ferroli F06 flue sensor fault, what causes it and how to fix it with clear steps. Check symptoms and order the right spare.
- [Ferroli F16 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/ferroli-f16/) - Fix the Ferroli F16 low water pressure fault with clear causes, checks and repair advice. Identify the issue fast and order the right part.
- [Ferroli F17 - No Water Circulation](https://boilerandspares.co.uk/fault-codes/ferroli-f17/) - Fix Ferroli F17 no water circulation faults with clear causes, checks and spare parts guidance. Identify the issue and order the right part.
- [Ferroli F18 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/ferroli-f18/) - Fix the Ferroli F18 rapid temperature rise fault with clear fault-code guidance, likely causes and parts advice. Identify the issue fast.
- [Ferroli F20 - DHW NTC Open Circuit](https://boilerandspares.co.uk/fault-codes/ferroli-f20/) - Fix the Ferroli F20 DHW NTC open circuit fault with clear diagnosis steps, common causes and parts guidance. Identify the right fix now.
- [Ferroli F21 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f21/) - Understand the Ferroli F21 outdoor sensor fault, common causes and practical fixes. Check symptoms and order the right Boiler Spares.
- [Ferroli F22 - Low Water Pressure (Pressure Switch)](https://boilerandspares.co.uk/fault-codes/ferroli-f22/) - Fix Ferroli F22 low water pressure faults with the right pressure switch guidance, clear compatibility details and order the correct part.
- [Ferroli F23 - Flow/Return Differential Too Large](https://boilerandspares.co.uk/fault-codes/ferroli-f23/) - Understand Ferroli F23 flow/return differential faults with clear causes, checks and parts guidance. Identify the fix and order spares.
- [Ferroli F24 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/ferroli-f24/) - Fix the Ferroli F24 frost protection active fault with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Ferroli F25 - PCB EEPROM Error](https://boilerandspares.co.uk/fault-codes/ferroli-f25/) - Fix Ferroli F25 PCB EEPROM faults with clear checks, likely causes and parts guidance from Boiler Spares. See the error code steps.
- [Ferroli F26 - Gas Valve Relay Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f26/) - See what an F26 gas valve relay fault means on a Ferroli boiler, common causes, and the parts to check. Use our guide to fix it fast.
- [Ferroli F27 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/ferroli-f27/) - Understand the Ferroli F27 fault code after shutdown, its likely causes and fix options. Identify the issue fast and order the right part.
- [Ferroli F29 - Ignition Electrode Worn](https://boilerandspares.co.uk/fault-codes/ferroli-f29/) - Fix the Ferroli F29 ignition electrode worn fault with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Ferroli F30 - External Thermostat Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f30/) - Fix the Ferroli F30 external thermostat fault with clear checks, likely causes and parts guidance from Boiler Spares. See the steps now.
- [Ferroli F31 - eBUS Communication Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f31/) - Understand the Ferroli F31 eBUS communication fault, common causes and practical checks, then identify the right spare part. Act now.
- [Ferroli F32 - Mains Voltage Error](https://boilerandspares.co.uk/fault-codes/ferroli-f32/) - Fix the Ferroli F32 mains voltage fault with clear causes, checks and repair guidance from Boiler Spares. Identify the issue and order parts.
- [Ferroli F33 - Combustion Quality Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f33/) - Fix the Ferroli F33 combustion quality fault with clear fault code guidance, likely causes and parts help from Boiler Spares. View the fix.
- [Ferroli F36 - Return NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/ferroli-f36/) - See what the Ferroli F36 return NTC short circuit fault code means, common causes and how to fix it. Check the fault and order the right part.
- [Ferroli F38 - Flow NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/ferroli-f38/) - Fix the Ferroli F38 flow NTC short circuit fault with clear causes, checks and parts guidance. Identify the issue and order spares.
- [Ferroli F40 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f40/) - Understand the Ferroli F40 pressure sensor fault, its likely causes and fixes, with clear fault advice and parts support. Check the guide.
- [Ferroli F44 - Cylinder Sensor Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f44/) - Understand Ferroli F44 cylinder sensor faults fast with clear causes, checks and fixes from Boiler Spares. Identify the issue and act.
- [Ferroli F45 - Coding Plug Missing](https://boilerandspares.co.uk/fault-codes/ferroli-f45/) - Fix the Ferroli F45 coding plug missing fault code with clear causes, part guidance and repair steps. Check the fault and order spares.
- [Ferroli F46 - Phase/Neutral Reversed](https://boilerandspares.co.uk/fault-codes/ferroli-f46/) - Fix the Ferroli F46 phase/neutral reversed fault with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Ferroli F47 - Pump Stuck](https://boilerandspares.co.uk/fault-codes/ferroli-f47/) - Fix a Ferroli F47 pump stuck fault with clear checks, likely causes and spare parts guidance. Identify the issue and order the right part.
- [Ferroli F48 - DHW Flow Switch Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f48/) - See what the Ferroli F48 DHW flow switch fault means, common causes and parts advice from Boiler Spares. Check the fix and order spares.
- [Ferroli F49 - Pump Over-Run Fault](https://boilerandspares.co.uk/fault-codes/ferroli-f49/) - See what the Ferroli F49 pump over-run fault code means, its common causes and likely fixes, with clear guidance to diagnose the issue.
- [Ferroli F50 - Diverter Valve Timeout](https://boilerandspares.co.uk/fault-codes/ferroli-f50/) - Fix the Ferroli F50 diverter valve timeout fault code with clear fault checks, likely causes and parts guidance. See the repair steps.
- [Ferroli F51 - Flame Signal Too Weak](https://boilerandspares.co.uk/fault-codes/ferroli-f51/) - Fix Ferroli F51 flame signal too weak faults with clear causes, checks and parts guidance from Boiler Spares. See the fault code steps.
- [Ferroli F53 - Fan Speed Error](https://boilerandspares.co.uk/fault-codes/ferroli-f53/) - Understand the Ferroli F53 fan speed fault code, its likely causes and practical fixes. Check symptoms and order the right boiler spares.
- [Ferroli F54 - Gas Valve Step Error](https://boilerandspares.co.uk/fault-codes/ferroli-f54/) - Understand the Ferroli F54 gas valve step error, common causes and repair advice from Boiler Spares. Check the fault code and next steps.
- [Ferroli F55 - Room Controller Lost](https://boilerandspares.co.uk/fault-codes/ferroli-f55/) - Fix the Ferroli F55 room controller lost fault code with clear checks, likely causes and spare part guidance. Identify the fault and order parts.
- [Alpha E16 - Maximum Temperature Exceeded](https://boilerandspares.co.uk/fault-codes/alpha-e16/) - The boiler water temperature has exceeded its absolute maximum limit.
- [Alpha E30 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/alpha-e30/) - The diverter valve (which switches flow between heating and hot water on a combi boiler) is not operating correctly.
- [Alpha E33 - PCB Internal Fault](https://boilerandspares.co.uk/fault-codes/alpha-e33/) - The PCB has detected an internal fault.
- [Alpha E40 - False Flame Detected](https://boilerandspares.co.uk/fault-codes/alpha-e40/) - An ionisation signal has been detected when no flame should be present.
- [Alpha E55 - Flow Temperature Overheat](https://boilerandspares.co.uk/fault-codes/alpha-e55/) - The flow temperature is excessively high, causing a protective lockout.
- [Alpha E70 - Chip Card / Configuration Error](https://boilerandspares.co.uk/fault-codes/alpha-e70/) - Fix Alpha E70 chip card or configuration errors with clear fault-code guidance and likely causes. Identify the issue and order the right part.
- [Alpha 1 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/alpha-1/) - The boiler has failed to ignite. Possible causes include gas supply issues, defective ignition electrode, faulty ignition lead, gas valve problem, or PCB fault.
- [Alpha 2 - Overheat Boiler Lockout](https://boilerandspares.co.uk/fault-codes/alpha-2/) - The boiler has overheated and locked out. Caused by pump or flow problems, blocked heat exchanger, air in system, or a faulty overheat thermostat.
- [Alpha 3 - High Flue Temperature](https://boilerandspares.co.uk/fault-codes/alpha-3/) - The flue gas temperature has reached a dangerous level. Usually caused by a blocked or restricted primary flow, blocked heat exchanger, flue restriction, or a flue sensor fault.
- [Alpha 4 - Gas Valve Electrical Connection Fault](https://boilerandspares.co.uk/fault-codes/alpha-4/) - There is an electrical connection fault at the gas valve — either the valve lead connection is faulty, the valve itself is defective, or the PCB is faulty.
- [Alpha 5 - Heating Flow Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-5/) - The central heating flow temperature sensor has a wiring fault or the sensor itself has failed.
- [Alpha 6 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-6/) - Fix Alpha 6 DHW sensor faults with clear causes, checks and part guidance from Boiler Spares. Identify the issue fast and order the right part.
- [Alpha 8 - Maximum Number of Resets Exceeded](https://boilerandspares.co.uk/fault-codes/alpha-8/) - The boiler has reached its maximum reset count. Refer to the fault history codes to identify the underlying fault.
- [Alpha 12 - Cylinder Sensor Fault (FlowSmart)](https://boilerandspares.co.uk/fault-codes/alpha-12/) - Fix Alpha 12 cylinder sensor faults with FlowSmart advice, likely causes and parts guidance from Boiler Spares. Check the code and order the right spares.
- [Alpha 15 - Internal Wiring Error](https://boilerandspares.co.uk/fault-codes/alpha-15/) - An incorrect wiring configuration has been detected internally. Usually only occurs after maintenance or installation work.
- [Alpha 16 - Fan Fault](https://boilerandspares.co.uk/fault-codes/alpha-16/) - The fan has a fault — either a wiring connection issue, a failed fan motor, or a PCB fan control fault.
- [Alpha 20 - Flame Sensing Fault](https://boilerandspares.co.uk/fault-codes/alpha-20/) - The flame sensing electrode is not detecting the flame correctly, or there is a PCB fault affecting the ionisation circuit.
- [Alpha 24 - Control Panel Button Fault](https://boilerandspares.co.uk/fault-codes/alpha-24/) - A control panel button is stuck in the ON position, or there is a fault with the PCB buttons.
- [Alpha 25 - Overheat Lockout (Secondary)](https://boilerandspares.co.uk/fault-codes/alpha-25/) - Fix Alpha 25 Overheat Lockout secondary faults with clear fault code guidance, likely causes and parts help. Check the repair steps.
- [Alpha 27 - Insufficient Primary Flow](https://boilerandspares.co.uk/fault-codes/alpha-27/) - The boiler is not detecting adequate water flow through the primary circuit. Caused by blockage, restricted flow, airlocks, closed valves, or pump fault.
- [Alpha 29 - Flue Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-29/) - The flue gas temperature sensor has a wiring fault or has failed.
- [Alpha 31 - Loss of Communication with External Control](https://boilerandspares.co.uk/fault-codes/alpha-31/) - Identify the Alpha 31 fault code for loss of communication control, its likely causes and fixes, then order the right Boiler Spares parts.
- [Alpha 37 - Low Supply Voltage](https://boilerandspares.co.uk/fault-codes/alpha-37/) - The mains power supply voltage has dropped below the minimum operating level for the boiler.
- [Alpha 38 - Loss of Flame Rectification (Type 1)](https://boilerandspares.co.uk/fault-codes/alpha-38/) - The boiler's flame rectification circuit has detected a fault with the flame — the electrode may be faulty, dirty, or there may be flue gas recirculation.
- [Alpha 43 - Loss of Flame Rectification (Type 2)](https://boilerandspares.co.uk/fault-codes/alpha-43/) - Persistent flame rectification loss — similar to code 38 but indicating a more established problem with the flame sensing circuit.
- [Alpha 44 - Safety Lockout — External Control Cycling](https://boilerandspares.co.uk/fault-codes/alpha-44/) - Guidance on Alpha 44 Safety Lockout caused by external control cycling, with fault checks and likely fixes. See the troubleshooting steps.
- [Alpha 46 - External Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-46/) - The optional external temperature sensor (for weather compensation) has a wiring fault or has failed.
- [Alpha 47 - Reduced Burner Output — Flue Thermostat Active](https://boilerandspares.co.uk/fault-codes/alpha-47/) - The flue thermostat has sensed high flue gas temperature and reduced the burner output as protection. If the temperature continues to rise, the boiler will lockout with code 3.
- [Alpha 49 - Return Sensor High Temperature](https://boilerandspares.co.uk/fault-codes/alpha-49/) - The return sensor has detected an unusually high temperature on the heat exchanger return circuit, indicating poor circulation.
- [Alpha 51 - Climatic RF Communication Fault](https://boilerandspares.co.uk/fault-codes/alpha-51/) - The wireless communication between the boiler and the Alpha Climatic remote control transmitter has failed. Could be low batteries, distance, or interference.
- [Alpha 60 - Pump Error (E-Tec / Evoke)](https://boilerandspares.co.uk/fault-codes/alpha-60/) - On Alpha E-Tec and Evoke combi boilers, code 60 indicates the pump is stuck or has an electrical fault.
- [Alpha 61 - Air in Pump / Restricted CH Flow (E-Tec / Evoke)](https://boilerandspares.co.uk/fault-codes/alpha-61/) - Fix Alpha 61 Air in Pump / Restricted CH Flow faults on E-Tec and Evoke boilers with clear code guidance and parts support. Check fixes.
- [Alpha 70 - Return/Flow Sensor Wiring Fault (E-Tec)](https://boilerandspares.co.uk/fault-codes/alpha-70/) - On Alpha E-Tec boilers, code 70 indicates a wiring or connection issue with the return or flow sensor.
- [Alpha 71 - No Primary Temperature Rise Detected (E-Tec Regular)](https://boilerandspares.co.uk/fault-codes/alpha-71/) - After ignition, the boiler has not detected a temperature rise in the primary circuit — indicating a serious circulation fault or airlock preventing heat from being distributed.
- [Alpha 0A1 - Ignition Failure (ProTec Plus)](https://boilerandspares.co.uk/fault-codes/alpha-0a1/) - On Alpha ProTec Plus commercial boilers, 0A1 indicates ignition failure — gas supply or valve issue.
- [Alpha 0A5 - Fan Speed Fault (ProTec Plus)](https://boilerandspares.co.uk/fault-codes/alpha-0a5/) - On Alpha ProTec Plus boilers, 0A5 indicates a fan speed fault — flue or ventilation issue.
- [Alpha SR - Service Reminder (E-Tec)](https://boilerandspares.co.uk/fault-codes/alpha-sr/) - Get the Alpha SR service reminder fault code explained clearly, with likely causes and practical fixes. Check symptoms and next steps.
- [Alpha E02 - Flame Supervision Fault](https://boilerandspares.co.uk/fault-codes/alpha-e02/) - Clear guide to the Alpha E02 flame supervision fault, with causes, checks and likely fixes. Identify the issue fast and view the steps.
- [Alpha E03 - Overheat Protection Activated](https://boilerandspares.co.uk/fault-codes/alpha-e03/) - See why the Alpha E03 fault code triggers overheat protection, what checks to make, and which boiler spares may fix it. Diagnose the fault.
- [Alpha E12 - DHW NTC Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-e12/) - Fix Alpha E12 DHW NTC sensor faults with clear checks, likely causes and part guidance from Boiler Spares. Use the guide now.
- [Alpha E13 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-e13/) - See what Alpha E13 means, the outdoor sensor issues it points to, and the likely fixes. Check the fault code and next steps.
- [Alpha E14 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-e14/) - Identify Alpha E14 pressure sensor faults fast with clear checks, likely causes and boiler spares guidance. See the fix steps now.
- [Alpha E17 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/alpha-e17/) - Understand the Alpha E17 gas valve fault, its likely causes and checks to try before you book a repair. See the fault guide now.
- [Alpha E18 - PCB Communication Error](https://boilerandspares.co.uk/fault-codes/alpha-e18/) - Understand the Alpha E18 PCB communication error, its likely causes and checks to try before replacing parts. See the fault code guide.
- [Alpha E19 - Fan Fault](https://boilerandspares.co.uk/fault-codes/alpha-e19/) - Fix Alpha E19 fan fault code with clear causes, checks and parts advice from Boiler Spares. Identify the issue fast and order the right spares.
- [Alpha E21 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/alpha-e21/) - Fix Alpha E21 condensate blocked fault code with clear fault checks, likely causes and spare part guidance. Identify the issue fast.
- [Alpha E22 - Flame Lost During Operation](https://boilerandspares.co.uk/fault-codes/alpha-e22/) - See what the Alpha E22 fault code means, why the flame cuts out during operation, and the parts to check. Identify the issue and order spares.
- [Alpha E23 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/alpha-e23/) - Fix the Alpha E23 low gas pressure fault with clear checks, likely causes and parts guidance. Identify the issue fast and view the next steps.
- [Alpha E24 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/alpha-e24/) - Understand the Alpha E24 air pressure switch fault code, common causes and likely fixes. Check symptoms and order the right spare part.
- [Alpha E26 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/alpha-e26/) - Fix the Alpha E26 diverter valve fault code with clear fault checks, likely causes and spare part guidance. See the steps and parts needed.
- [Alpha E27 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/alpha-e27/) - Understand the Alpha E27 rapid temperature rise fault code, its likely causes and fixes, then check the right boiler spares.
- [Alpha E29 - Flow/Return Differential Fault](https://boilerandspares.co.uk/fault-codes/alpha-e29/) - Fix the Alpha E29 flow/return differential fault with clear fault-code guidance, likely causes and part checks. Identify the next step.
- [Alpha E31 - Pump Fault](https://boilerandspares.co.uk/fault-codes/alpha-e31/) - Understand the Alpha E31 pump fault code, its common causes and fixes, with clear guidance to diagnose the issue and order the right spare.
- [Alpha E32 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/alpha-e32/) - Understand Alpha E32 EEPROM fault codes with clear causes, checks and repair guidance from Boiler Spares. Identify the issue and fix it fast.
- [Alpha E35 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/alpha-e35/) - Understand Alpha E35 frost protection active fault codes, common causes and practical checks to restore heating. See the fault guide.
- [Alpha E36 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/alpha-e36/) - Fix Alpha E36 flue gas overheat faults with clear code guidance, likely causes and parts advice from Boiler Spares. Check the remedy.
- [Alpha E37 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/alpha-e37/) - Understand Alpha E37 eBUS fault codes fast with clear causes, likely fixes and spare part guidance. Check the fault and order the right part.
- [Alpha E38 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/alpha-e38/) - Alpha E38 fault code explained with mains voltage checks and fix steps. See likely causes, parts advice and what to do next.
- [Alpha E39 - Return NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/alpha-e39/) - Identify the Alpha E39 return NTC short circuit fault, its likely causes and the parts you may need. Check the code and order spares.
- [Alpha E41 - Flow NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/alpha-e41/) - Fix Alpha E41 flow NTC short circuit faults with clear cause checks and part guidance from Boiler Spares. Identify the issue and order parts.
- [Alpha E42 - DHW NTC Short Circuit](https://boilerandspares.co.uk/fault-codes/alpha-e42/) - Fix Alpha E42 DHW NTC short circuit faults with clear causes, checks and parts guidance from Boiler Spares. View the code details now.
- [Alpha E43 - Combustion Quality Fault](https://boilerandspares.co.uk/fault-codes/alpha-e43/) - Fix Alpha E43 combustion quality faults with clear checks, likely causes and parts advice from Boiler Spares. Identify the issue and order the right part.
- [Alpha E44 - Flame Detected After Shutdown](https://boilerandspares.co.uk/fault-codes/alpha-e44/) - Fix the Alpha E44 fault code for flame after shutdown with clear checks, likely causes and parts guidance. See the steps to diagnose it.
- [Alpha E45 - Coding Plug Fault](https://boilerandspares.co.uk/fault-codes/alpha-e45/) - See what the Alpha E45 coding plug fault means, common causes and practical fixes to diagnose the issue quickly. Check the fault guide.
- [Alpha E01 - Ignition Failure](https://boilerandspares.co.uk/fault-codes/alpha-e01/) - The boiler has failed to ignite — the burner attempted to light but no flame was detected.
- [Alpha E10 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/alpha-e10/) - The system water pressure has dropped below 0.6 bar — the minimum required for an Alpha boiler to operate safely.
- [Alpha E20 - Flame Failure / No Flame Detected](https://boilerandspares.co.uk/fault-codes/alpha-e20/) - The boiler cannot detect a flame. The burner has failed to light or the ionisation electrode is not detecting the flame correctly.
- [Alpha E25 - Dry Fire / Low Water Detected](https://boilerandspares.co.uk/fault-codes/alpha-e25/) - The boiler has attempted to fire without detecting sufficient water flow, indicating very low water pressure or a flow sensor fault.
- [Alpha E28 - Flue Fault](https://boilerandspares.co.uk/fault-codes/alpha-e28/) - There is a problem with the flue — it may be blocked, incorrectly installed, or the flue temperature sensor may have failed.
- [Alpha E34 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/alpha-e34/) - The boiler has reached an unsafe temperature and the overheat thermostat has triggered a lockout.
- [Alpha E50 - DHW Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-e50/) - The domestic hot water temperature sensor is giving an incorrect reading or has failed.
- [Alpha E60 - Fan Fault](https://boilerandspares.co.uk/fault-codes/alpha-e60/) - The fan is not operating at the required speed or has stopped working.
- [Alpha E90 - Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/alpha-e90/) - The air pressure switch is not registering correctly — this switch confirms that the fan is running before allowing gas to flow.
- [Alpha E96 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/alpha-e96/) - The gas valve has an electronic fault and is not operating correctly.
- [Alpha E04 - High Limit Thermostat Tripped](https://boilerandspares.co.uk/fault-codes/alpha-e04/) - The high-limit (STB) safety thermostat has activated due to excessive temperature, cutting the gas supply.
- [Alpha E05 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-e05/) - The return temperature sensor (NTC thermistor) has failed or has a wiring fault.
- [Alpha E06 - Flue Sensor Fault](https://boilerandspares.co.uk/fault-codes/alpha-e06/) - The flue gas temperature sensor is giving an out-of-range reading.
- [Alpha E07 - Overheat Sensor Tripped](https://boilerandspares.co.uk/fault-codes/alpha-e07/) - The main overheat safety sensor (STB) has activated due to excessive boiler temperature.
- [Alpha E08 - Flue Overheat Sensor Tripped](https://boilerandspares.co.uk/fault-codes/alpha-e08/) - The flue temperature sensor has detected dangerously high exhaust temperatures.
- [Alpha E09 - Fan Fault — No Air Pressure](https://boilerandspares.co.uk/fault-codes/alpha-e09/) - The fan has not generated sufficient air pressure for the air pressure switch to confirm safe combustion conditions.
- [Alpha E11 - Return Temperature Too High](https://boilerandspares.co.uk/fault-codes/alpha-e11/) - The return temperature from the heating circuit is higher than expected, indicating possible circulation issues.
- [Alpha E15 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/alpha-e15/) - Fix Alpha E15 low gas pressure faults with clear code guidance and boiler spares support. Check likely causes and order the right part.
- [Potterton E33 - Flame Instability](https://boilerandspares.co.uk/fault-codes/potterton-e33/) - Fix Potterton E33 flame instability faults with clear causes, checks and parts guidance from Boiler Spares. Diagnose the issue fast.
- [Potterton E34 - Condensate Blocked](https://boilerandspares.co.uk/fault-codes/potterton-e34/) - Fix Potterton E34 condensate blocked faults with clear causes, checks and parts guidance from Boiler Spares. Diagnose the issue now.
- [Potterton E35 - Rapid Temperature Rise](https://boilerandspares.co.uk/fault-codes/potterton-e35/) - Fix Potterton E35 rapid temperature rise faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Potterton E36 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e36/) - See what the Potterton E36 pressure sensor fault means, what causes it and which boiler spares may fix it, then check the right part.
- [Potterton E37 - Safety Thermostat Open](https://boilerandspares.co.uk/fault-codes/potterton-e37/) - Fix Potterton E37 safety thermostat open faults with clear causes, checks and parts advice from Boiler Spares. See the next steps.
- [Potterton E38 - Flue Gas Overheat](https://boilerandspares.co.uk/fault-codes/potterton-e38/) - See what Potterton E38 means, what causes flue gas overheating, and the parts often linked to it. Check likely fixes before booking a repair.
- [Potterton E39 - Frost Protection Active](https://boilerandspares.co.uk/fault-codes/potterton-e39/) - See what Potterton E39 frost protection active fault code means, the likely causes, and practical checks before you arrange a repair.
- [Potterton E41 - Three-Way Valve Timeout](https://boilerandspares.co.uk/fault-codes/potterton-e41/) - Fix Potterton E41 three-way valve timeout faults with clear causes, checks and parts guidance. Identify the issue fast and order spares.
- [Potterton E42 - Outdoor Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e42/) - See what the Potterton E42 outdoor sensor fault means, common causes and practical fixes, then check the right boiler spares.
- [Potterton E43 - eBUS Fault](https://boilerandspares.co.uk/fault-codes/potterton-e43/) - Understand Potterton E43 eBUS fault codes, common causes and practical fixes. Identify the issue faster and check the right next steps.
- [Potterton E44 - Mains Voltage Fault](https://boilerandspares.co.uk/fault-codes/potterton-e44/) - Fix a Potterton E44 mains voltage fault with clear checks, likely causes and parts guidance from Boiler Spares. See the repair steps.
- [Potterton E45 - EEPROM Error](https://boilerandspares.co.uk/fault-codes/potterton-e45/) - Understand the Potterton E45 EEPROM error, its likely causes and the parts you may need to fix it. Check the fault guide now.
- [Potterton E46 - Coding Plug Fault](https://boilerandspares.co.uk/fault-codes/potterton-e46/) - Understand Potterton E46 coding plug faults, likely causes and part checks with Boiler Spares guidance. Identify the issue and order the right spare.
- [Potterton E47 - Pump Kickback Fault](https://boilerandspares.co.uk/fault-codes/potterton-e47/) - Fix Potterton E47 pump kickback faults with clear checks, likely causes and parts guidance. Identify the issue fast and view the guide.
- [Potterton E48 - Phase/Neutral Reversed](https://boilerandspares.co.uk/fault-codes/potterton-e48/) - Fix a Potterton E48 phase/neutral reversed fault with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Potterton E119 - Low Water Pressure](https://boilerandspares.co.uk/fault-codes/potterton-e119/) - System pressure has dropped below the required minimum of 0.5 bar. Shared with Baxi boilers — Potterton and Baxi share the same fault code system.
- [Potterton E133 - Ignition Failure / Frozen Condensate](https://boilerandspares.co.uk/fault-codes/potterton-e133/) - The boiler has failed to ignite. In winter, the most common cause is a frozen condensate pipe.
- [Potterton E110 - Overheat Lockout](https://boilerandspares.co.uk/fault-codes/potterton-e110/) - The boiler has overheated and the safety thermostat has triggered.
- [Potterton E160 - Fan Fault](https://boilerandspares.co.uk/fault-codes/potterton-e160/) - The boiler fan is not operating at the correct speed or has stopped working altogether.
- [Potterton E168 - PCB Lockout / Unspecified Fault](https://boilerandspares.co.uk/fault-codes/potterton-e168/) - The PCB has detected a fault it cannot specifically identify and has locked out the boiler.
- [Potterton E125 - Primary Circulation Fault](https://boilerandspares.co.uk/fault-codes/potterton-e125/) - There is insufficient water circulation in the primary heating circuit.
- [Potterton E151 - PCB Error (Type 1)](https://boilerandspares.co.uk/fault-codes/potterton-e151/) - The PCB has detected an internal fault of type 1.
- [Potterton E164 - Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e164/) - The water pressure sensor is giving an out-of-range signal. May indicate a blocked or failed sensor.
- [Potterton E128 - Frequent Flame Failure](https://boilerandspares.co.uk/fault-codes/potterton-e128/) - The boiler has lost its flame 12 times in succession and entered a safety lockout.
- [Potterton E131 - Flue Overheat](https://boilerandspares.co.uk/fault-codes/potterton-e131/) - The flue temperature has reached an unsafe level, triggering the flue thermostat.
- [Potterton E135 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/potterton-e135/) - The air pressure switch is not registering correctly — this confirms the fan is running before gas is allowed to flow.
- [Potterton E28 - Frozen Condensate / Flame Failure (Winter)](https://boilerandspares.co.uk/fault-codes/potterton-e28/) - Flame failure associated with a frozen condensate pipe in cold weather. Identical to Baxi E28 — Potterton and Baxi share the same fault code system.
- [Potterton E53 - Condensate Pipe Blocked](https://boilerandspares.co.uk/fault-codes/potterton-e53/) - The condensate system is blocked, preventing the boiler from operating safely.
- [Potterton E10 - Flow Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e10/) - The flow temperature sensor has failed or has a wiring fault.
- [Potterton E11 - Return Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e11/) - The return temperature sensor has failed or has a wiring fault.
- [Potterton E20 - Flame Failure Lockout](https://boilerandspares.co.uk/fault-codes/potterton-e20/) - The boiler has failed to detect a flame after the ignition sequence.
- [Potterton E116 - High Flow Temperature](https://boilerandspares.co.uk/fault-codes/potterton-e116/) - Fix Potterton E116 high flow temperature faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Potterton E220 - Gas Valve Not Opening](https://boilerandspares.co.uk/fault-codes/potterton-e220/) - The gas valve has received the signal to open but hasn't responded correctly.
- [Potterton E40 - Thermistor / Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/potterton-e40/) - A temperature sensor has short-circuited, causing the boiler to lock out.
- [Potterton E50 - DHW NTC Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e50/) - The domestic hot water temperature sensor has a fault on combi boiler models.
- [Potterton E78 - Water Pressure Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e78/) - The water pressure sensor is giving an incorrect reading. May indicate a blocked or failed sensor.
- [Potterton E83 - Room Controller Communication Fault](https://boilerandspares.co.uk/fault-codes/potterton-e83/) - The boiler cannot communicate with the room controller — may be a wiring fault or controller failure.
- [Potterton E84 - Room Controller Not Recognised](https://boilerandspares.co.uk/fault-codes/potterton-e84/) - The room controller connected to the boiler is not being recognised by the PCB.
- [Potterton E117 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/potterton-e117/) - The gas valve has a fault — it may not be opening, closing, or responding to PCB commands correctly.
- [Potterton E130 - Flue Thermostat Tripped](https://boilerandspares.co.uk/fault-codes/potterton-e130/) - The flue safety thermostat has triggered due to excessively high flue gas temperatures.
- [Potterton E152 - PCB Error (Type 2)](https://boilerandspares.co.uk/fault-codes/potterton-e152/) - Fix Potterton E152 PCB Error Type 2 with clear fault code guidance, likely causes and compatible Boiler Spares parts. Check the fix now.
- [Potterton E161 - Fan Fault (Secondary)](https://boilerandspares.co.uk/fault-codes/potterton-e161/) - A secondary fan fault code on Potterton boilers — fan speed or operation is outside expected parameters.
- [Potterton E270 - Dry Fire Detected](https://boilerandspares.co.uk/fault-codes/potterton-e270/) - The boiler has fired or attempted to fire without detecting adequate water circulation — a 'dry fire' condition.
- [Potterton E09 - Gas Valve Wiring Fault](https://boilerandspares.co.uk/fault-codes/potterton-e09/) - There is a fault in the wiring to the gas valve — either the connection cable has a fault or the gas valve itself is defective.
- [Potterton E12 - Differential Water Flow Switch — Remains Open](https://boilerandspares.co.uk/fault-codes/potterton-e12/) - The differential water flow switch is remaining open when it should be closed. Indicates a circulation issue or a faulty flow switch.
- [Potterton E13 - Differential Water Flow Switch — Remains Closed](https://boilerandspares.co.uk/fault-codes/potterton-e13/) - The differential water flow switch is stuck in the closed position. Indicates a faulty switch or wiring issue.
- [Potterton E15 - Gas Valve Command Fault](https://boilerandspares.co.uk/fault-codes/potterton-e15/) - There is a fault with the gas valve command signal from the PCB to the valve. The valve is not responding to open/close commands correctly.
- [Potterton E55 - Calibration Required](https://boilerandspares.co.uk/fault-codes/potterton-e55/) - The boiler requires calibration — this code appears on auto-calibrating models when the combustion setup needs to be verified or adjusted.
- [Potterton E92 - Combustion Test Alarm During Auto-Setting](https://boilerandspares.co.uk/fault-codes/potterton-e92/) - An alarm has been triggered during the automatic combustion calibration process. The auto-setting procedure detected a combustion issue.
- [Potterton E109 - Poor Circulation / Pre-Circulation Fault](https://boilerandspares.co.uk/fault-codes/potterton-e109/) - The boiler has detected insufficient water circulation during its pre-circulation check. Usually caused by airlocks, closed valves, or a failing pump.
- [Potterton E129 - Frequent Flame Loss — Safety Lockout](https://boilerandspares.co.uk/fault-codes/potterton-e129/) - The boiler has experienced repeated flame loss during operation — a persistent version of the flame failure fault that has triggered a full lockout.
- [Potterton E134 - Gas Valve Open Without Gas](https://boilerandspares.co.uk/fault-codes/potterton-e134/) - The gas valve has been commanded open but no gas has been detected flowing — the timer for gas detection has elapsed.
- [Potterton E154 - Flow/Return Sensor Temperature Test Failure](https://boilerandspares.co.uk/fault-codes/potterton-e154/) - The boiler has performed an internal temperature sensor cross-check and found the flow or return sensor reading to be incorrect or implausible.
- [Potterton E163 - DHW NTC Sensor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e163/) - The domestic hot water temperature sensor has a fault — short circuit or open circuit. On combi models.
- [Potterton E317 - Wrong Power Supply Frequency](https://boilerandspares.co.uk/fault-codes/potterton-e317/) - The boiler is detecting an incorrect mains power frequency (should be 50Hz in the UK). This may indicate a power supply issue.
- [Potterton E321 - Hot Water Thermistor Fault](https://boilerandspares.co.uk/fault-codes/potterton-e321/) - The hot water temperature thermistor has a fault — applies to store/system boilers with a hot water cylinder.
- [Potterton E384 - False Flame — Gas Valve Off](https://boilerandspares.co.uk/fault-codes/potterton-e384/) - Fix Potterton E384 false flame gas valve off faults with clear causes, checks and parts advice from Boiler Spares. See the code guide now.
- [Potterton E385 - Low Voltage — Under 195V](https://boilerandspares.co.uk/fault-codes/potterton-e385/) - The mains voltage supply to the boiler has dropped below 195V — below the minimum operating voltage.
- [Potterton E430 - Water Pressure Test / Test Failed](https://boilerandspares.co.uk/fault-codes/potterton-e430/) - The boiler is performing a water pressure test (normal on commissioning) or the test has failed, indicating a potential system leak.
- [Potterton E14 - Low Gas Pressure](https://boilerandspares.co.uk/fault-codes/potterton-e14/) - Fix Potterton E14 low gas pressure faults with clear causes, checks and parts guidance from Boiler Spares. Identify the issue and order the right part.
- [Potterton E16 - Fan Fault](https://boilerandspares.co.uk/fault-codes/potterton-e16/) - Understand Potterton E16 fan fault codes with clear causes, checks and spare part guidance. Identify the fault fast and order the right part.
- [Potterton E18 - Ignition Electrode Fault](https://boilerandspares.co.uk/fault-codes/potterton-e18/) - Genuine Potterton E18 ignition electrode fault spares with fast UK delivery and clear part matching. Order the right replacement online.
- [Potterton E19 - Gas Valve Fault](https://boilerandspares.co.uk/fault-codes/potterton-e19/) - Understand Potterton E19 gas valve faults fast with clear checks, likely causes and parts advice from Boiler Spares. See the fix steps.
- [Potterton E21 - Flow Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/potterton-e21/) - Fix Potterton E21 flow sensor short circuit faults with clear checks, likely causes and parts guidance. Identify the issue and order spares.
- [Potterton E22 - Flow Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/potterton-e22/) - Fix Potterton E22 flow sensor open circuit faults with clear checks, likely causes and spare part guidance. See the fault code steps.
- [Potterton E23 - Return Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/potterton-e23/) - Fix a Potterton E23 return sensor short circuit with fault code causes, checks and matching boiler spares. Identify the part and order yours.
- [Potterton E24 - Return Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/potterton-e24/) - Fix Potterton E24 return sensor open circuit faults with clear checks, likely causes and parts guidance. See the fault code steps now.
- [Potterton E25 - DHW Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/potterton-e25/) - See what the Potterton E25 fault code means, why a DHW sensor short circuit occurs, and the parts to check. Use our guide to fix the fault.
- [Potterton E26 - DHW Sensor Open Circuit](https://boilerandspares.co.uk/fault-codes/potterton-e26/) - See what the Potterton E26 DHW Sensor Open Circuit fault code means, common causes and likely fixes. Check the fault and order the right spare.
- [Potterton E27 - Air Pressure Switch Fault](https://boilerandspares.co.uk/fault-codes/potterton-e27/) - Fix a Potterton E27 air pressure switch fault with clear code guidance, likely causes and parts advice. Check symptoms and order spares.
- [Potterton E30 - Diverter Valve Fault](https://boilerandspares.co.uk/fault-codes/potterton-e30/) - See why the Potterton E30 fault points to a diverter valve issue, what symptoms to check, and the right spare part to order. Diagnose it now.
- [Potterton E31 - PCB Communication Fault](https://boilerandspares.co.uk/fault-codes/potterton-e31/) - Understand Potterton E31 PCB communication fault codes with likely causes, checks and parts support. Identify the fault and order spares.
- [Potterton E32 - Pump Fault](https://boilerandspares.co.uk/fault-codes/potterton-e32/) - Understand the Potterton E32 pump fault, what causes it and how to fix it fast with clear steps. Check the fault and order parts.
- [Glow-worm F25 - Circulation Fault (All Ranges)](https://boilerandspares.co.uk/fault-codes/glow-worm-f25/) - On all Glow-worm boiler ranges, F25 (or F23) indicates a circulation fault — insufficient water flow through the primary circuit.
- [Glow-worm F01 - Return Temperature Sensor Fault (Betacom/Ultracom)](https://boilerandspares.co.uk/fault-codes/glow-worm-f01/) - On Glow-worm Betacom and Ultracom models, F01 (or F11) indicates a return heating temperature sensor fault.
- [Glow-worm F76 - Thermal Fuse Fault (Betacom/Ultracom)](https://boilerandspares.co.uk/fault-codes/glow-worm-f76/) - Fix the Glow-worm F76 fault on Betacom and Ultracom boilers with clear thermal fuse checks, likely causes and parts guidance. Diagnose now.
- [Glow-worm F86 - Underfloor Heating Contact Fault](https://boilerandspares.co.uk/fault-codes/glow-worm-f86/) - On Glow-worm boilers connected to underfloor heating systems, F86 indicates a fault with the underfloor heating contact or switching circuit.
- [Glow-worm F6 - CH Flow Thermistor Fault (Older Ranges)](https://boilerandspares.co.uk/fault-codes/glow-worm-f6/) - On older Glow-worm ranges, F6 indicates a central heating flow thermistor fault.
- [Glow-worm F7 - DHW Thermistor Fault (Older Ranges)](https://boilerandspares.co.uk/fault-codes/glow-worm-f7/) - Fix Glow-worm F7 DHW thermistor faults on older ranges with clear fault checks, likely causes and parts guidance. Identify the issue now.
- [Glow-worm F10 - CH Return Thermistor Fault (Older Ranges)](https://boilerandspares.co.uk/fault-codes/glow-worm-f10/) - On older Glow-worm ranges, F10 indicates a central heating return thermistor fault.
- [Glow-worm F14 - Gas Valve Control Defective (Older Ranges)](https://boilerandspares.co.uk/fault-codes/glow-worm-f14/) - On Glow-worm Flexicom and Ultracom models, F14 indicates the gas valve control is defective.
- [Glow-worm F15 - eBUS Voltage Fault (Older Ranges)](https://boilerandspares.co.uk/fault-codes/glow-worm-f15/) - On Glow-worm Flexicom and Ultracom models, F15 indicates an eBUS voltage failure.
- [Glow-worm F43 - Generic Internal Error (Flexicom/Ultracom)](https://boilerandspares.co.uk/fault-codes/glow-worm-f43/) - On Glow-worm Flexicom and Ultracom models, F43 indicates a generic internal fault code.
- [Glow-worm F2 - Flame Supervision Fault](https://boilerandspares.co.uk/fault-codes/glow-worm-f2/) - Fix Glow-worm F2 flame supervision faults with clear checks, likely causes and parts guidance. Identify the issue fast and order spares.
- [Glow-worm F3 - Flue Gas Sensor Fault](https://boilerandspares.co.uk/fault-codes/glow-worm-f3/) - Understand Glow-worm F3 flue gas sensor fault codes, common causes and fixes, with clear fault guidance to help you diagnose the issue.
- [Glow-worm F8 - Return NTC Sensor Short Circuit](https://boilerandspares.co.uk/fault-codes/glow-worm-f8/) - Fix the Glow-worm F8 return NTC sensor short circuit fault with clear checks, likely causes and parts guidance. Diagnose the issue now.
- [Glow-worm F17 - Gas Valve Closing Fault](https://boilerandspares.co.uk/fault-codes/glow-worm-f17/) - Fix the Glow-worm F17 gas valve closing fault with clear fault code advice, likely causes and parts guidance. Check the repair steps.

## Categories

- [General](https://boilerandspares.co.uk/category/general/)
- [Plumbing](https://boilerandspares.co.uk/category/plumbing/)

## Fault Categories

- [Sensor Fault](https://boilerandspares.co.uk/fault-type/sensor/)
- [Overheat](https://boilerandspares.co.uk/fault-type/overheat/)
- [Pressure Fault](https://boilerandspares.co.uk/fault-type/pressure/)
- [Circulation Fault](https://boilerandspares.co.uk/fault-type/circulation/)
- [Flue Fault](https://boilerandspares.co.uk/fault-type/flue/)
- [Gas Valve Fault](https://boilerandspares.co.uk/fault-type/gas/)
- [Flame Fault](https://boilerandspares.co.uk/fault-type/flame/)
- [Ignition Fault](https://boilerandspares.co.uk/fault-type/ignition/)
- [Fan Fault](https://boilerandspares.co.uk/fault-type/fan/)
- [Electronics Fault](https://boilerandspares.co.uk/fault-type/electronics/)
- [Pump Fault](https://boilerandspares.co.uk/fault-type/pump/)
- [Valve Fault](https://boilerandspares.co.uk/fault-type/valve/)
- [Electrical](https://boilerandspares.co.uk/fault-type/electrical/)
- [Status](https://boilerandspares.co.uk/fault-type/status/)
- [Controls](https://boilerandspares.co.uk/fault-type/controls/)
- [Leak](https://boilerandspares.co.uk/fault-type/leak/)
- [Heating](https://boilerandspares.co.uk/fault-type/heating/)
- [Combustion](https://boilerandspares.co.uk/fault-type/combustion/)
- [Condensate](https://boilerandspares.co.uk/fault-type/condensate/)