Halstead was a British boiler manufacturer based in Essex, popular with installers from the 1980s through to the 2000s. Acquired by Glen Dimplex, Halstead withdrew from the market in 2012. Their Ace, Ace High, Best, Eden, Finest, and Hero ranges are still found in many UK homes. Spare parts are increasingly difficult to source.
Halstead Boiler Fault Codes
All Halstead Fault Codes 15
| Code | Fault | Severity | Type | View guide |
|---|---|---|---|---|
| 1 | Ignition Lockout The boiler has failed to ignite and locked out. On older Halstead models this is… | High | Engineer | View Guide |
| 10 | Diverter Valve Fault The diverter valve is stuck or not switching correctly between heating and hot water. This… | Medium | Engineer | View Guide |
| 11 | Differential Check Failure The temperature difference between flow and return is outside expected limits. Indicates a circulation problem. | Medium | Engineer | View Guide |
| 12 | Low Water Pressure System water pressure has dropped below the minimum safe level. | Low | DIY Check | View Guide |
| 13 | Pump Fault The circulation pump is not running or has seized. | High | Engineer | View Guide |
| 14 | Condensate Blocked The condensate drain is blocked or frozen. | Medium | DIY Check | View Guide |
| 15 | Flue Gas Overheat The flue gas temperature has exceeded safe limits. | High | Engineer | View Guide |
| 2 | Overheat Lockout The safety thermostat has activated due to overheating. The boiler has shut down to prevent… | High | Engineer | View Guide |
| 3 | Fan / Air Pressure Switch Fault The fan is not running correctly or the air pressure switch is not confirming airflow. | High | Engineer | View Guide |
| 4 | Flame Loss During Operation The boiler had a stable flame but lost it during operation. May indicate gas supply… | High | Engineer | View Guide |
| 5 | Return Thermistor Fault The return water temperature sensor is reading outside its normal range. | Medium | Engineer | View Guide |
| 6 | Flow Thermistor Fault The flow water temperature sensor is faulty or reading incorrectly. | Medium | Engineer | View Guide |
| 7 | DHW Thermistor Fault The domestic hot water temperature sensor has developed a fault. | Medium | Engineer | View Guide |
| 8 | PCB / Electronics Fault The printed circuit board has an internal error. On Halstead Ace High models, PCB failure… | High | Engineer | View Guide |
| 9 | Gas Valve Fault The gas valve is not responding to commands. The solenoid may be faulty. | High | Engineer | View Guide |