16 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Economy Plus
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Your boiler's small starter flame is cutting out unexpectedly, which stops the main heater from running.
Your boiler is failing to shut down when it reaches the required temperature, which means the water inside may keep heating up unnecessarily.
Your boiler has detected that it is running too hot and has automatically switched itself off as a safety precaution to prevent damage.
Your boiler is vibrating or making unusual banging or whistling noises while running, which often indicates trapped air in the system or a build-up of internal debris.
Your boiler has lost its electrical power supply, meaning it cannot start up to provide heating or hot water.
Your boiler appears to have no power reaching it, which is likely caused by an external electrical issue or a blown fuse inside the unit.
Your boiler has detected that it is getting too hot and has automatically switched itself off to prevent damage.
Your boiler has switched itself off because it has reached an unsafe temperature or a safety sensor has detected a fault.
Your boiler has stopped working because it cannot safely clear waste gases, which prevents it from igniting to protect your home.
Your boiler has stopped working because it cannot confirm that the internal fan is safely clearing waste gases from the system.
Your boiler has failed to start up or stay burning, meaning it cannot produce heat or hot water because it has stopped the gas flow as a safety precaution.
Your boiler has failed to light the pilot flame or cannot verify that the burner is safely lit, resulting in no heating or hot water.
Your boiler is not receiving the correct electrical power, meaning it cannot start the ignition process to provide heating or hot water.
Your boiler has likely stopped heating because it has reached an unusually high internal temperature and has shut down as a safety precaution.
Your boiler has detected an internal electrical communication error, meaning it cannot safely confirm the fan is working to clear waste gases.
Your boiler is unable to light the pilot flame, which means it cannot fire up to provide heating or hot water.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes