18 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
This boiler uses LED flash patterns
Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →
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Your boiler's computer is experiencing a temporary processing confusion that has caused it to stop working to protect the system.
Your boiler's internal computer is experiencing a critical error and cannot safely operate the system.
Your boiler has failed to light the flame, so it has safely shut itself down to prevent a gas build-up.
Your boiler is experiencing a general internal fault that is preventing it from operating correctly.
Your boiler is operating exactly as it should and is successfully firing up to heat your water or radiators.
Your boiler has stopped working as a safety precaution and needs to be manually restarted to see if it can clear the internal error.
Your boiler is operating normally and performing its job of heating water as expected.
Your boiler has failed to light the flame and has turned itself off for safety.
Your boiler is failing to clear air from the system before starting, which is preventing it from firing up safely.
Your boiler is operating normally and the flame is successfully lit to provide your heating or hot water.
Your boiler is correctly receiving power and is in standby mode, awaiting a signal to provide heating or hot water.
Your boiler is correctly receiving a signal to provide heating or hot water and is working exactly as it should.
Your boiler is struggling because the internal fan is stuck running without the system actually igniting to produce heat.
Your boiler is operating normally and the main burner is currently lit to provide heat or hot water.
Your boiler has detected that it is overheating and has automatically switched itself off to prevent damage or dangerous conditions.
Your boiler has stopped working because it cannot light the internal flame or keep it burning safely.
Your boiler has stopped working because it has detected an issue with the water temperature or the ignition process and needs to be reset.
Your boiler has stopped because it failed to light or stay lit, which means you currently have no heating or hot water.
BoilerFaultCodes