16 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 internal computer brain has developed a fault and can no longer control the heating process safely.
Your boiler's main internal control board has developed a fault and can no longer send signals to operate the heating safely.
Your boiler has stopped working because of a loose connection or a fault in the internal electrical wiring that links its control parts together.
Your boiler's internal computer has developed a fault and is no longer able to control the heating process safely.
Your boiler has detected that it is trying to heat up without enough water flowing through it, causing it to shut down to prevent overheating.
Your boiler has detected a problem with its internal temperature sensors and has stopped working to prevent damage.
Your boiler's internal control board has developed an electrical fault and is no longer able to manage the heating process safely.
Your boiler has detected that it is heating up internally without enough water flowing through it, causing it to shut down to prevent damage.
Your boiler has detected a temperature sensor fault, meaning it can no longer accurately monitor how hot the water is getting.
Your boiler's main internal computer has developed a fault and is no longer able to control the heating process safely.
Your boiler has detected that the fan, which safely clears waste gases away, is not spinning correctly and has shut down the system for safety.
Your boiler has tried to light several times without success and has now shut itself down for safety.
Your boiler has no power reaching it, which means the system cannot start up to provide heating or hot water.
Your boiler is not receiving the signal from your thermostat or programmer to turn on, meaning it thinks it doesn't need to heat your home.
Your boiler has shut itself down because it has become too hot to operate safely.
Your boiler has detected that its temperature sensor is not working correctly, which means it cannot tell how hot the water is and has stopped running for safety.
BoilerFaultCodes