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Johnson & Starley

Aquastar 1 25

Combi Boiler 25kW 2010-2016 ErP A 36 fault codes

<p>The Aquastar 1 25 is a combi boiler from Johnson & Starley, available at 25kW output. Produced 2010-2016.</p>

Aquastar 1 25 Fault Codes 36

Code Description Severity Type
1 Ignition Failure (Numeric Display) On Johnson & Starley models with numeric displays, code 1 indicates flame lockout after several ignition… Medium DIY View Guide
2 Flame Failure Flame lost. High Engineer View Guide
3 Overheat (Numeric Display) On Johnson & Starley models with numeric displays, code 3 indicates the high water temperature limit… High Engineer View Guide
37 Low Water Pressure (Numeric Display) On Johnson & Starley numeric display models, code 37 indicates low system water pressure. Low DIY View Guide
4 APS Fault Air pressure switch issue. High Engineer View Guide
5 Overheat Overheat protection. High Engineer View Guide
E01 Ignition Lockout The most common Johnson & Starley fault. The boiler has failed to ignite after multiple attempts.… Medium DIY View Guide
E02 False Flame Lockout The boiler's ionisation circuit has detected a flame when the gas valve should be closed. Safety-critical… High Engineer View Guide
E03 Overheat Lockout The boiler has overheated and the safety thermostat has triggered a lockout. High Engineer View Guide
E04 Return NTC Fault Return sensor faulty. Medium Engineer View Guide
E05 Fan Fault The boiler fan is not operating correctly - not starting, running too slowly, or speed sensor… High Engineer View Guide
E06 Fan Fault Fan not operating. High Engineer View Guide
E07 Gas Valve Fault Gas valve not responding. High Engineer View Guide
E08 Flame Circuit Failure There is a fault in the flame monitoring circuit on the Johnson & Starley boiler's control… High Engineer View Guide
E09 Gas Valve Feedback Error The gas valve is not responding correctly to control commands, or there is a feedback signal… High Engineer View Guide
E10 Overheat Safety thermostat activated. High Engineer View Guide
E11 PCB Fault Internal PCB error. High Engineer View Guide
E12 EEPROM Lockout There is a memory fault on the PCB. The boiler's configuration data cannot be read or… High Engineer View Guide
E13 Low Pressure System pressure too low. Low DIY View Guide
E14 Pump Fault Pump not running. High Engineer View Guide
E15 Condensate Blocked Condensate pipe blocked. Medium DIY View Guide
E16 DHW NTC Fault Hot water sensor faulty. Medium Engineer View Guide
E17 Diverter Valve Fault Valve stuck. Medium Engineer View Guide
E18 APS Fault Air pressure switch fault. High Engineer View Guide
E19 Flame Instability Flame signal fluctuating. High Engineer View Guide
E20 Flame Lost Flame lost during operation. High Engineer View Guide
E21 Rapid Temperature Rise Flow temp rising too fast. High Engineer View Guide
E22 Combustion Fault Air/gas mixture outside limits. High Engineer View Guide
E23 Pressure Sensor Fault Sensor faulty. Medium Engineer View Guide
E24 Frost Protection Frost protection active. Medium DIY View Guide
E33 Return Thermistor Fault The return temperature sensor has a fault - open circuit, short circuit, or wiring issue. Medium Engineer View Guide
E35 Flow Thermistor Fault The flow temperature sensor has a fault. Medium Engineer View Guide
F37 Low Water Pressure The system water pressure is too low for safe operation on Johnson & Starley boilers. Low DIY View Guide
F40 Water Pressure Too High The system water pressure is too high - above 3 bar. Medium Engineer View Guide
F52 DHW Sensor Fault The domestic hot water temperature sensor has a fault. Medium Engineer View Guide
F53 Flue Temperature Sensor Lockout The flue gas temperature sensor has triggered a lockout due to excessive flue temperatures or a… High Engineer View Guide

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