60 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your heater has automatically shut down because its internal temperature sensor has detected that it is getting dangerously hot.
Your boiler has detected that the water coming back from your radiators is dangerously hot and has shut down to protect itself.
Your boiler has detected that water is heating up too quickly because it isn't moving through the system fast enough.
Your boiler is overheating too quickly, causing it to shut down to prevent damage.
Your boiler has detected that the water pressure is getting too low to run effectively, which will eventually cause the heating to stop working.
Your boiler has detected that the water is getting too hot too quickly, usually because it isn't flowing through the system properly.
Your boiler has detected an issue with the sensor that monitors water movement, meaning it cannot properly manage the temperature or flow of your heating.
Your boiler has detected an unstable electrical supply from the national grid or your home wiring, causing it to shut down for safety.
Your boiler's computer parts are having trouble talking to each other, which prevents the system from starting up.
Your heater is attempting to start up, but the internal fan is moving too slowly to safely begin the heating process.
Your heater has stopped working because the fan that safely clears exhaust gases is not spinning or receiving power.
Your boiler is currently running at its maximum power setting because a service mode used for testing has been activated.
Your boiler has tried to light several times but cannot start a flame, which means your heating and hot water will not work.
Your boiler has shut down because it has reached an unsafe temperature and needs to be cooled down and reset.
Your boiler has detected a problem with how it is venting exhaust gases or an issue with internal air pressure, causing it to shut down for safety.
Your boiler has stopped working because the water pressure is too low for it to run safely.
Your boiler has stopped providing heating because a temperature sensor responsible for monitoring water flow has developed a fault.
Your boiler is struggling to accurately measure the temperature of your hot water due to a faulty internal sensor.
Your boiler has stopped working because the fan that safely clears away exhaust gases is not spinning correctly.
Your heater's internal computer has encountered a software data error and is unable to communicate with its own settings.
Your boiler has lost its connection to the thermostat or external controller, meaning the two devices can no longer talk to each other to manage your heating.
Your boiler thinks it sees a fire burning before it has even started the ignition process, so it has shut down for safety.
Your boiler has failed to light the gas burner after several attempts and has locked itself for safety.
Your boiler has overheated because it reached a temperature that is too high for safe operation.
Your boiler has stopped running as a safety precaution and needs a manual reset to attempt to restart.
Your boiler has stopped working because the water inside it is not moving around properly to heat your home.
Your boiler has stopped working because the internal fan used for safe combustion is not spinning or cannot be detected by the system control board.
Your boiler has detected that a temperature sensor responsible for your central heating is reporting an incorrect or impossible reading.
Your boiler has detected an issue with the sensor that measures hot water temperature, which means you may not have reliable hot water for your taps and showers.
Your boiler's outdoor weather sensor is reporting an incorrect temperature, which may cause your heating to respond inefficiently to the weather outside.
Your boiler has detected a communication problem with the safety sensor that monitors exhaust gases, causing the system to shut down for safety.
Your boiler has detected an electrical fault with the sensor that monitors exhaust gases and has shut down as a safety precaution.
Your boiler thinks it sees a flame even though it hasn't started yet, which is a safety conflict that prevents it from turning on.
Your boiler's internal sensor has detected an unusual temperature reading on the pipe returning from your radiators, suggesting a sensor fault or water flow issue.
Your heater has automatically switched off because the internal temperature has become too hot.
Your boiler has shut down because it detected a sudden, unsafe rise in temperature, likely caused by water not flowing through the system correctly.
Your boiler has detected that the water is getting too hot too quickly because it isn't moving through the system properly.
Your boiler has detected that the water temperature difference between its pipes is too high, causing it to shut down to prevent overheating.
Your boiler has stopped working because it cannot detect water moving through the system to keep it cool during the startup process.
Your boiler has stopped working because water is not moving through the system properly, which could be due to a blockage or a pump issue.
Your boiler is struggling to provide hot water because the sensor that monitors the temperature of the incoming cold water has stopped working correctly.
Your boiler has detected a problem with a temperature sensor that monitors water returning to the unit, which is preventing it from heating properly.
Your heater tried to light several times but could not detect a flame, causing the system to lock out for safety.
Your boiler has lost its connection to the sensor that checks the water pressure, causing the system to stop working for safety.
Your boiler's main internal computer has developed a programming error or is not communicating correctly with the rest of the unit.
Your heater is trying to turn on but cannot light the burner, meaning your heating will not work until the system is reset or repaired.
Your boiler has failed to light the flame and has locked itself out for safety.
Your boiler has stopped working because the water pressure inside the system has dropped too low for it to operate safely.
Your boiler is not firing up because it isn't receiving the correct signal from your thermostat or internal controllers to start the heating process.
Your boiler has detected that the water pressure is too low for it to operate safely, which is why it has stopped working.
Your boiler has detected a problem with the sensor that monitors the safety of the exhaust gases, and it has shut down to prevent overheating.
Your boiler is unable to release gas into the burner to create a flame, meaning your heating will not work.
Your boiler has tried to start but cannot light the flame, causing it to shut down for safety.
Your boiler is currently running in a special test mode used by engineers to check its performance and it is not a technical fault.
Your boiler has lost power entirely, which is usually caused by a tripped switch at the fuse box or a fault with the electrical supply to the unit.
Your boiler is receiving power but fails to respond when the heating is scheduled to turn on, likely due to a communication failure between the controls and the unit.
Your boiler has become too hot and has automatically shut down to prevent damage to the internal components.
Your boiler has switched itself off because it has become too hot and needs time to cool down safely.
Your boiler is currently set to its installer configuration mode, meaning it is waiting for a professional to adjust its internal settings.
Your boiler is notifying you that its maximum power setting has been manually limited, often for efficiency or to match the specific size of your home.
BoilerFaultCodes