23 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has stopped working because it cannot maintain a stable flame or there is a blockage in the pipe that drains away moisture produced during operation.
Your boiler has detected that it is getting too hot and has automatically shut down to prevent damage or dangerous overheating.
Your boiler is struggling to clear exhaust fumes or draw in fresh air, so it has safely shut down to prevent any risk of harmful gases escaping.
Your boiler is struggling to circulate water, most likely because the pressure inside your system has dropped too low to operate safely.
Your boiler is struggling to accurately measure the temperature of the water it is heating, so it has stopped working to prevent potential overheating.
Your boiler has lost the ability to accurately measure the temperature of the water being sent to your radiators, so it has safely shut down to prevent overheating.
Your boiler has detected an issue with its internal ventilation system four times in a row, causing it to shut down for safety reasons.
Your boiler has detected that a safety sensor is stuck in the 'on' position before the fan has even started, so it has stopped working as a precaution.
Your boiler has lost the ability to accurately measure the temperature of its internal heat exchanger, so it has safely shut down to prevent overheating.
Your boiler has detected that hot water is not flowing through your heating system correctly, which is causing it to shut down to prevent overheating.
Your boiler has detected that hot water isn't moving around your radiators or pipes properly and has shut itself down to prevent overheating.
Your boiler is failing to detect the necessary electrical power to operate, which may be caused by a loose wire or an issue with your heating controls.
Your boiler has detected a flame when it shouldn't be there, which means it has safely shut down to prevent a dangerous situation.
Your boiler has stopped working because it cannot accurately measure the temperature of the water flowing through the system.
Your boiler has stopped working because it failed to light the flame after several attempts, so it has shut itself down for safety.
Your boiler has failed to start after several attempts and is now safely preventing itself from turning on to protect your home.
Your boiler has completely lost the electrical signal it needs to start running, meaning it is currently unable to provide any heating or hot water.
Your boiler has automatically turned itself off because it has become dangerously hot and needs to cool down before it can be used again.
Your boiler has switched itself off because it has become too hot and needs a manual reset to restart.
Your boiler has detected that it has become too hot and has automatically shut itself down to prevent internal damage.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler's internal computer has stopped working correctly and is no longer able to safely manage the heating system.
Your boiler has detected an issue with the sensor that monitors its temperature, which prevents it from heating your home or water safely.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes