20 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is performing a routine cool-down cycle after heating your home and is not actually experiencing a fault.
Your boiler has reached the target temperature and is taking a short, normal break before it starts heating again.
Your boiler is performing a routine automatic safety check on its internal sensors, which it does once every day.
Your boiler is currently trying to light the flame using electrical sparks, which is a normal part of its startup sequence.
Your boiler is currently working as normal and is simply indicating that it is heating your radiators.
Your boiler is simply letting you know that it is currently busy heating up water for your taps or shower.
Your boiler has stopped working because the internal fan that safely removes waste gases isn't spinning at the correct speed.
Your boiler has stopped working because it is unable to accurately read the temperature of the water inside the system.
Your boiler has stopped working because it is unable to accurately read the temperature of the water inside the system.
Your boiler has stopped working because it cannot correctly read its internal temperature, causing it to shut down for safety.
Your boiler has stopped working because it is unable to accurately read the temperature of the water inside the system due to a faulty sensor connection.
Your boiler has stopped working because it is unable to accurately read the temperature of the water inside the system.
Your boiler has stopped working because one of its internal temperature sensors is providing an invalid or missing reading, preventing the system from safely heating your water.
Your boiler has stopped working because one of its internal temperature sensors is providing an inaccurate reading, preventing the system from safely heating your home or water.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water inside the system due to a faulty sensor.
Your boiler's internal temperature monitor is failing to report accurate information, so the system has stopped operating to prevent potential overheating.
Your boiler is unable to read the temperature correctly because one of its internal sensors is sending an invalid signal, causing the system to stop working as a safety precaution.
Your boiler has lost connection with the sensor that measures the temperature outside, which may cause your heating to behave unpredictably.
Your boiler has detected an internal issue with the component that manages the gas flow, meaning it cannot safely start up to provide heating or hot water.
Your boiler has detected an internal issue with the part that manages the gas supply, meaning it has safely shut down to prevent unsafe operation.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes