38 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has stopped working as a safety precaution because it failed to light the flame or maintain it correctly.
Your boiler has detected that it is dangerously overheating and has automatically switched itself off to prevent permanent damage.
Your boiler has stopped working as a safety precaution and will not restart on its own.
Your boiler has detected that water is not circulating correctly through the system, which is preventing it from heating your home or water safely.
Your boiler has detected an issue with the internal ventilation system that pushes out waste gases, causing it to shut down for safety reasons.
Your boiler is struggling to read the outdoor temperature, which may cause your heating to run less efficiently or shut down as a precaution.
Your boiler is struggling because it has lost the signal from the sensor that measures how cold it is outside.
Your boiler is struggling because a thermal sensor inside the flue is sending incorrect readings, causing the system to stop working to stay safe.
Your boiler has detected that the gases it produces are getting too hot, so it has safely shut itself down to prevent any damage.
Your boiler has detected an issue with the ignition process and is stopping itself from firing up to keep your home safe.
Your boiler has stopped heating the water because it cannot move the liquid around the system properly, which has caused it to shut down for safety.
Your boiler is struggling to move water around the system properly, which is causing it to overheat and shut itself down for safety.
Your boiler is confused because it detects temperature changes in the wrong order, likely caused by a sensor issue or a plumbing component being fitted incorrectly.
Your boiler has lost the ability to accurately measure the temperature of the water circulating inside it, so it has safely shut down to prevent overheating.
Your boiler has detected that there is not enough water circulating inside the system to operate safely.
Your boiler is failing to light the flame or keep it running, which means it has safely shut itself down to prevent gas from building up.
Your boiler has stopped working because a sensor that measures the temperature of the water coming back into the system has developed a fault or is sending an incorrect signal.
Your boiler has stopped working because it cannot light the flame required to produce heat or hot water.
Your boiler has switched itself off because it has detected an overheating issue, which prevents it from operating until the fault is corrected.
Your boiler's internal computer is experiencing a communication error and has shut down for safety, meaning you currently have no heating or hot water.
Your boiler has detected that the water pressure inside your heating system is too low to operate safely and effectively.
Your boiler has detected that there is either not enough water inside the system or that the water is not circulating correctly, which prevents it from heating your home.
Your boiler is struggling to clear exhaust gases safely, so it has turned itself off to prevent any risk.
Your boiler has detected an issue with the internal ventilation system that pushes out waste gases, causing it to shut down for safety reasons.
Your boiler has stopped working because it cannot correctly read the temperature of the water circulating through your heating system.
Your boiler is struggling to accurately measure its own internal water temperature, so it has shut down to prevent overheating.
Your boiler is struggling to read the outdoor temperature, which might affect its ability to adjust your heating automatically based on the weather.
Your boiler is struggling because it has lost the signal from an outdoor thermometer that helps it adjust your heating based on the weather.
Your boiler has detected an issue with its exhaust system or the sensor that monitors exhaust heat, causing it to shut down for safety.
Your boiler has detected an issue with the sensor that monitors the exhaust gas temperature, causing it to shut down for safety.
Your boiler has detected that the temperature in the exhaust flue is incorrect, which means it will stop working to ensure your safety.
Your boiler has detected an issue with water flow or heat blockage within its internal heating system, causing it to stop working to protect itself.
Your boiler is struggling to circulate water properly or clear waste gases, causing it to shut down to prevent damage.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water circulating through your heating system due to a faulty sensor connection.
Your boiler has stopped working because it cannot correctly measure the temperature of the water circulating inside the heating system.
Your boiler has lost the ability to accurately measure the temperature of the water circulating through your radiators, so it has shut down as a precaution to prevent overheating.
Your boiler has detected an issue with the water flow around your radiators, suggesting the pump that pushes water through your heating system is not working correctly.
Your boiler has detected that hot water is not circulating properly around your radiators, meaning your heating system cannot function correctly.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes