12 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 is struggling because it detects both a faulty water temperature sensor and low water pressure, which has caused it to stop working to protect itself.
Your boiler's internal control brain is unable to talk to the rest of the unit, meaning it has shut down for your safety and will not provide heating or hot water.
Your boiler has detected that it has become too hot and has automatically shut itself down to prevent damage.
Your boiler is currently unable to run because the water pressure inside the heating system has dropped too low.
Your boiler's temperature sensor is providing an incorrect reading, which has caused the system to stop heating for your safety.
Your boiler is having trouble 'reading' the temperature of your hot water, which may prevent it from heating your taps correctly.
Your boiler has stopped working because it cannot light its internal flame or keep it burning.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler has stopped working because a sensor that measures water temperature is providing an incorrect reading or has failed, causing the system to shut down for safety.
Your boiler has detected a serious internal problem and has completely shut itself down as a safety precaution, meaning you currently have no heating or hot water.
Your boiler has entered a safety lockout mode and stopped working because it has detected an internal fault that it cannot resolve on its own.
Your boiler has detected a minor, short-term hiccup in its internal systems and is currently running normally again.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes