21 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected an internal communication or hardware failure on its main control board, meaning it has safely shut down to prevent further issues.
Your boiler's built-in timer or programmer has a flat backup battery, meaning it may lose the correct time and schedule if the power goes off.
Your boiler's control panel switch is not registering properly, which means the system may not respond to your heating and hot water settings.
Your boiler has detected an issue with the control knob settings or user interface connection.
Your boiler is having trouble reading its internal water pressure, which usually means the system pressure is too low or the pressure gauge needs attention.
Your boiler has safely shut down because it detected that the temperature in the exhaust flue is too high or the safety sensor has tripped.
Your boiler has detected an issue with the water pump that circulates heating around your home, meaning your heating and hot water may not work properly.
Your boiler has automatically shut down because the internal water temperature reached an unsafe level.
Your boiler has temporarily stopped working because a temperature sensor is giving incorrect readings, meaning it cannot safely regulate your hot water.
Your boiler has stopped working because it has detected a problem with the water pressure inside the system.
Your boiler's temperature sensor has encountered a technical glitch, meaning the system cannot accurately monitor the heat of the water it is pumping around your radiators.
Your boiler has lost the ability to measure the temperature of your hot water, which usually means it will stop providing hot water or provide it at an inconsistent temperature.
Your boiler has detected a problem with the sensor that monitors the temperature of the exhaust gases, causing the system to shut down for safety.
Your boiler has switched itself off because the water inside it has become too hot, which is a safety precaution to prevent damage.
Your boiler has stopped working because the water pressure is too low for the system to run safely.
Your boiler is struggling to move water around the system effectively, causing it to overheat and shut down for safety.
Your boiler has shut down because the exhaust gases have reached a temperature that is too high, indicating a potential blockage or a serious internal circulation issue.
Your boiler has experienced a power cut or was switched off while it was already showing a different fault, causing it to lock itself out for safety.
Your boiler is failing to light the gas burner, meaning it cannot provide heating or hot water until the issue is resolved.
Your boiler has stopped working because the fan that clears away waste gases is not spinning correctly or communicating with the control system.
Your boiler has detected that water is not circulating correctly through the system before the heating process starts, causing it to shut down to prevent damage.
BoilerFaultCodes