17 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 currently operating in a restricted safety mode and is not providing heat to your radiators as it normally should.
Your boiler is unable to light the flame needed to heat your water and home.
Your boiler has shut down because it has detected it is getting too hot, triggering a safety switch to prevent damage.
Your boiler has detected an issue with how it is getting rid of exhaust fumes, which has caused it to shut down for safety.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler's temperature sensor for the central heating system has failed or developed a fault, meaning the boiler cannot accurately gauge how hot the water is.
Your boiler's temperature sensor for hot water has stopped working correctly, meaning your taps and showers may not get warm or could stay cold.
Your boiler has shut down because a sensor detected that the water inside has become far too hot.
Your boiler's computer brain has encountered a serious internal error and cannot safely light the burner to provide heat or hot water.
Your boiler has detected that the water inside it is getting dangerously hot and has shut itself down to prevent damage or overheating.
Your boiler's internal computer has flagged a critical error that prevents it from starting up reliably.
Your boiler is currently running a self-diagnostic test or combustion check and does not have a functional fault.
Your boiler's internal setting that helps provide instant hot water has been switched off or is not being recognised.
Your boiler has lost its internal configuration settings, meaning it has forgotten whether it should be running on natural gas or LPG, or is experiencing a communication fault with its control settings.
Your boiler's internal settings have become confused due to a misplaced internal electronic pin, which is preventing the heating system from switching on correctly.
Your boiler has detected an internal issue and is preventing itself from igniting to stay safe.
Your boiler has stopped working because it cannot sense a flame, meaning it is locked out for safety reasons.
BoilerFaultCodes