5 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 has detected that the internal fan, which safely clears exhaust gases, is not spinning or communicating correctly with the system.
Your boiler has detected a problem with the internal temperature sensor that controls your central heating, meaning it cannot safely monitor how hot the water is getting.
Your boiler has detected that water is not circulating correctly through the system, which has likely caused it to shut down to prevent overheating.
Your boiler has switched itself off for safety because it has detected an internal temperature that is too high.
Your boiler has stopped working because it couldn't light the flame, which has triggered a safety lockout to prevent issues.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes