92 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 error or a software glitch that is preventing the system from starting up safely.
Your boiler is reporting a communication problem or a technical fault with your solar heating system, though your central heating should continue to work.
Your boiler is taking a short, programmed break to prevent itself from turning on and off too frequently, which helps protect the internal components and improve efficiency.
Your boiler has detected an issue with the air fan system and has safely shut down to prevent the appliance from starting incorrectly.
Your boiler has shut down because a safety sensor has detected that it is getting far too hot, likely due to a blockage or a pump failure.
Your boiler has switched itself off because it has detected it is getting too hot, usually caused by the water pressure being too low.
Your boiler is failing to light the gas even though it is trying to, which prevents your heating and hot water from working.
Your boiler is failing to light the flame properly, meaning you will not have any heating or hot water until the issue is resolved.
Your boiler thinks a flame is burning even though it hasn't actually sparked or started, causing it to shut down for safety.
Your boiler thinks it can see a flame even though it hasn't started the ignition process yet, which prevents it from running for safety reasons.
Your boiler started to heat up but the flame went out unexpectedly, causing the system to shut down for safety.
Your boiler has been turned off by an external control, such as a smart thermostat, a safety switch, or a heating zone controller.
Your boiler's computer has lost the ability to identify itself and requires a professional reset or part replacement.
Your boiler has detected an electrical problem with the component that controls the gas supply, meaning it cannot safely light the burner to provide heat or hot water.
Your boiler's internal computer parts are having trouble communicating because they don't recognise each other's software versions.
Your boiler's computer has detected an internal communication error and has shut down as a safety precaution.
Your boiler's internal computer has encountered a critical error and can no longer communicate with the rest of the system.
Your boiler has experienced an internal electrical error that is preventing it from firing up to provide heating or hot water.
Your boiler's internal computer has encountered a communication error or logic conflict, causing the system to stop working for safety.
Your boiler’s internal computer has encountered a critical communication error and can no longer process instructions.
Your boiler’s internal computer has encountered a communication error or internal glitch that is preventing it from running properly.
Your boiler's main internal computer has encountered a communication error and needs a reset to try and clear the glitch.
Your boiler's internal computer is experiencing a software or logic error, preventing it from processing information correctly.
Your boiler’s internal computer has encountered a communication error or an internal glitch and cannot operate until it is reset or repaired.
Your boiler's internal computer has encountered a software or hardware communication error, preventing it from starting up correctly.
Your boiler's internal computer brain is experiencing a critical communication error or software glitch that is preventing it from running.
Your boiler's internal computer has encountered a software or communication error and cannot operate properly.
Your boiler's internal computer has encountered a software or hardware communication error and has stopped working to protect itself.
Your boiler's internal computer has encountered a software or communication error and can no longer control the heating process.
Your boiler's internal computer has encountered a communication error or a software fault and cannot operate correctly.
Your boiler’s internal computer has encountered a software or hardware error and can no longer communicate with the rest of the system.
Your boiler is temporarily pausing because it is producing more heat than your radiators or hot water system can currently use or circulate.
Your boiler is struggling to detect a flame when it tries to start, which means it cannot fire up to provide heating or hot water.
Your boiler has paused its operation because it has been running continuously for 24 hours and needs to perform a brief internal safety check.
Your boiler's internal pump is unable to move water because it is jammed or contains trapped air, stopping your heating from working.
Your boiler is still detecting a flame even though it has tried to shut off the gas supply, which is a safety conflict.
Your boiler is still detecting a flame even after it has tried to shut off the gas, which is a safety conflict that requires a professional inspection.
Your boiler’s internal computer has encountered a memory error or is having trouble communicating with its own control board.
Your boiler's internal computer has lost communication with its identification chip or the chip installed is the wrong model for this unit.
Your boiler has developed a serious internal electronic failure that means it can no longer recognize its own control system.
Your boiler has encountered an internal communication error between its main electronic control boards, meaning it cannot currently function or heat your home.
Your boiler has stopped working because its internal computer has detected a communication error with the burner control system.
Your boiler's internal computer has lost its connection to its main controls, meaning it cannot receive the instructions it needs to provide heating or hot water.
Your boiler has stopped working because the water pressure is too low and needs to be topped up.
Your boiler is struggling to accurately measure the temperature of your hot water, which usually means your taps aren't getting hot enough or stay cold.
Your boiler is unable to provide hot water because it cannot accurately measure how hot the water is.
Your boiler's internal thermometer that measures the water returning from your radiators has developed a fault and can no longer read the temperature correctly.
Your boiler has lost connection with its outdoor thermometer, meaning it might not adjust its heating efficiently based on the weather outside.
Your boiler has detected an issue with the sensor that monitors internal water pressure, meaning it cannot confirm if there is enough water to operate safely.
Your boiler's internal water pressure sensor is not communicating properly with the control board, preventing the system from operating safely.
Your boiler is struggling to work out how hard it needs to fire because the sensor that monitors the weather outside has stopped sending a signal.
Your boiler has detected an electrical fault with an internal temperature sensor, preventing the system from monitoring heat levels safely.
Your boiler has lost communication with its internal temperature sensor, meaning it cannot monitor heat levels and has shut down as a safety precaution.
Your boiler has encountered an internal software or communication error that is preventing it from heating your home.
Your boiler's internal computer has encountered a communication error or internal electronic glitch that is preventing it from working correctly.
Your boiler is struggling to safely expel exhaust gases, which has caused the system to shut down for safety.
Your boiler's internal computer has detected a general electrical communication error and is unable to operate correctly.
Your boiler's main internal computer has encountered a memory or communication error, preventing the system from running safely.
Your boiler has detected an internal electrical communication error, meaning it cannot properly coordinate its functions to provide heat and hot water.
Your boiler has detected a problem with how it tracks its own flame, causing it to shut down for safety purposes.
Your boiler has stopped working because it cannot confirm that the flame is properly lit, causing the system to shut down for safety.
Your boiler has detected an internal electrical communication error, which means it has stopped running to prevent damage to its electronic components.
Your boiler has detected an internal electrical problem that is preventing it from starting up safely.
Your boiler has experienced an internal electrical error that has caused it to stop working for safety.
Your boiler's internal computer has detected a general electrical communication error and has shut down as a safety precaution.
Your boiler's internal computer has encountered a software or hardware error that is preventing it from running properly.
Your boiler's main internal computer has encountered a processing error and cannot communicate correctly with the system.
Your boiler has detected an internal communication error or hardware fault within its main control system, preventing it from firing up safely.
Your boiler's computer memory chip is not being recognised or is mismatched, which prevents the system from starting up.
Your boiler's internal computer chip is either missing or has failed, meaning the system doesn't know which specific model it's supposed to be.
Your boiler is struggling to stay lit when it is running at its lowest power level, often causing it to shut down for safety.
Your boiler is struggling to keep its flame lit during operation, which is causing it to stop and restart frequently.
Your boiler is failing to detect a flame when it tries to work at a high power level, causing it to shut down for safety.
Your boiler has tried to start up but cannot detect a flame, meaning it cannot provide heating or hot water.
Your boiler is trying to light itself but cannot detect a flame, meaning your heating and hot water will likely stop working.
Your boiler is struggling to keep its burner lit and has turned itself off for safety after several failed attempts to maintain a steady flame.
Your boiler has detected an internal error while trying to check if the flame is burning safely, causing the system to shut down for safety.
Your boiler’s internal computer has been given instructions that it doesn't recognize or that don't match how the unit is physically built.
Your boiler has detected an internal electrical communication error, which means it has stopped working as a safety precaution.
Your boiler has stopped working because the internal computer cannot communicate with the fan that safely clears away exhaust fumes.
Your boiler has stopped working because the internal computer cannot communicate with the fan that safely clears away used gases.
Your boiler has detected that the sensors monitoring its internal temperature are giving incorrect readings or have failed, causing the system to shut down for safety.
Your boiler has detected an unusual temperature reading because a sensor or its wiring is not communicating correctly with the main control unit.
Your boiler has sensed that the water inside is getting much hotter than it should be and has shut down as a safety precaution.
Your boiler has shut down because the water inside is getting much hotter than it should be, which is often caused by a blockage or a pump failure preventing the heat from moving away.
Your boiler is overheating too quickly because water isn't moving through the system fast enough.
Your boiler is heating up too quickly and has shut down to prevent damage, usually because water isn't flowing through the system fast enough.
Your boiler has detected that the water pressure in your heating system is falling much faster than normal, which usually indicates a significant leak or a fault with the pressure sensor.
Your boiler has detected that the water pressure in your radiators is falling much faster than expected, which could indicate a significant leak.
Your boiler has detected that the water pressure in the system has dropped below the minimum level required to operate safely.
Your boiler has detected that the water pressure in your heating system is too low to operate safely and effectively.
Your boiler has detected that the electricity supply coming from your home's mains or the local grid is too low for it to operate safely.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes