74 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has shut down because it has detected that the water leaving the unit is getting too hot, which is usually caused by a circulation problem.
Your boiler has sensed that the water returning from your radiators is far too hot, causing the system to shut down to prevent damage.
Your boiler has shut down because the exhaust gases have become too hot, which is a safety measure to prevent damage to the internal components.
Your boiler has tried to light several times but has failed, likely because gas is not reaching the burner or the spark is not working.
Your boiler has tried to start several times but cannot light the gas to begin heating.
Your boiler has detected an internal electrical fault with the component that controls the gas supply, meaning it cannot safely ignite for heating or hot water.
Your boiler has detected an internal electrical fault with the component that controls the gas supply, meaning it cannot safely ignite.
Your boiler's internal computer has detected a safety control failure and has locked itself down as a precaution.
Your boiler has detected an internal electrical safety failure and has shut down to prevent an unsafe operating condition.
Your boiler has detected an internal electrical safety failure and has shut down to prevent damage or unsafe operation.
Your boiler's internal computer brain is having trouble processing information and has temporarily stopped working.
Your boiler's electronic memory chip has developed a software or communication fault, preventing the system from running safely.
Your boiler is unable to start up safely because the fan that removes waste gases is not spinning correctly.
Your boiler's computer memory has encountered a software error and can no longer communicate correctly with the main control board.
Your boiler's computer memory has developed a technical fault, preventing it from remembering the settings it needs to operate safely.
Your boiler has sensed that the water leaving the unit is getting too hot and has shut down as a safety precaution.
Your boiler's internal computer memory is not communicating correctly with the main control board, preventing the system from starting.
Your boiler has shut down and is running the fan at full speed because the exhaust gases have become dangerously hot.
Your boiler is detecting a flame remaining inside the unit for a few seconds after it should have been shut off.
Your boiler has stopped working because the fan that removes waste gases cannot spin at the correct speed.
Your boiler has shut down completely for safety reasons because it failed to light a flame.
Your boiler has shut down completely because a safety sensor has detected that the system is overheating.
Your boiler has shut down because a safety sensor has detected a problem with how the flue gases are being cleared or handled.
Your boiler has shut down to protect itself because a safety sensor has detected a fault with the burner or the ignition process.
Your boiler has switched itself off for safety reasons because a internal component or the system itself is not operating correctly.
Your boiler has shut down completely because a safety sensor has detected an internal issue and locked the system for protection.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault or has overheated.
Your boiler has shut down completely because one of its safety sensors has detected a problem with the internal temperature or pressure.
Your boiler has shut down completely because an internal safety sensor has detected a critical fault that requires a professional inspection.
Your boiler has switched itself off for safety because it has detected a problem with internal pressure or a safety sensor has been triggered.
Your boiler has shut itself down for safety because a internal limit or protection switch has been triggered.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault or overheating.
Your boiler has shut itself down as a safety precaution because one of its internal sensors has detected a potential overheating or pressure issue.
Your boiler has shut itself down for safety because it detects a serious internal issue that is preventing it from running properly.
Your boiler has shut itself down for safety because a central control unit or an internal monitoring device has detected a serious fault.
Your boiler has shut down completely because one of its safety sensors has detected a problem with the internal temperature or pressure.
Your boiler has shut itself down as a safety precaution because one of its internal protection systems has detected a fault.
Your boiler has shut itself down for safety because a internal limit was exceeded, likely due to overheating or a lack of water circulation.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault that could lead to overheating or unsafe operation.
Your boiler has switched itself off completely as a protective measure because its internal safety sensors have detected a critical operating fault.
Your boiler has shut itself down for safety because a critical fault has been detected that requires a manual reset.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault that needs professional attention.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault that could lead to overheating or unsafe operation.
Your boiler has shut itself down as a safety precaution because one of its internal safety sensors has detected a potential fault.
Your boiler has shut down because it has detected an internal safety issue, likely related to overheating or a lack of water circulation.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault or overheating.
Your boiler has shut itself down for safety because a critical fault or overheating has been detected.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault that could lead to overheating or poor performance.
Your boiler has shut down completely because a safety sensor has detected an internal fault that requires a professional inspection.
Your boiler has shut itself down as a safety precaution because it has detected an internal fault that could lead to overheating or unsafe operation.
Your boiler has shut itself down as a safety precaution because it has detected a serious internal fault that could be related to combustion or basic operation.
Your boiler system has lost communication with the secondary control boards that help manage the heating demand.
Your boiler has detected an electrical issue with its power supply or wiring, meaning it cannot safely start the burner.
Your boiler has detected an issue with the electrical power supply coming from the grid or your home's wiring, meaning the electricity frequency is incorrect for it to operate safely.
Your boiler has stopped working because the internal water pressure is too low for the system to run safely.
Your boiler's computer memory has developed a communication fault and can no longer process its stored settings.
Your boiler has detected an electrical wiring issue where the power supply wires are crossed, preventing it from safely lighting the flame.
Your boiler has detected a fault with the sensor that monitors exhaust fumes, causing the system to shut down for safety.
Your boiler has lost connection with a safety sensor that monitors the temperature of the exhaust gases, causing the system to shut down for protection.
Your boiler has detected an issue with the electrical power supply frequency coming into your home.
Your boiler's internal computer parts are having trouble talking to each other, causing the system to stop working.
Your boiler has stopped working because one of its internal temperature sensors has developed an electrical fault and is reporting incorrect information.
Your boiler has stopped working because it cannot get a temperature reading from the main pipe where hot water leaves the unit.
Your boiler has detected a fault with the sensor that monitors the water returning to the unit, causing the system to stop working for safety.
Your boiler has lost connection with the sensor that monitors water returning from your radiators, meaning it cannot safely regulate its temperature.
Your boiler has shut down because a temperature sensor has detected that the water leaving the system is getting too hot.
Your boiler has detected that the water returning to the unit is too hot, causing it to shut down for safety.
Your boiler has detected that the exhaust gases are getting too hot, causing the fan to run at full speed to protect the system from damage.
Your boiler has detected that the water inside the system is dangerously hot and has automatically shut itself down to prevent damage.
Your boiler has detected that the water returning from your radiators is dangerously hot and has shut itself down to prevent damage.
Your boiler has detected that the exhaust gases are becoming dangerously hot and has shut itself down to prevent internal damage.
Your boiler has detected a safety concern or internal error and has shut down to protect your home until it is manually restarted.
Your boiler has experienced a temporary glitch that has now cleared itself, meaning the system is likely operating normally again.
Your boiler's main computer control panel is reporting a general failure, meaning it cannot communicate correctly to start the heating process.
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