129 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has temporarily stopped because it cannot safely get rid of its exhaust gases, meaning your heating and hot water have turned off for your safety.
Your boiler has temporarily shut down because an internal safety thermostat detected that the water inside reached too high a temperature.
Your boiler has tried to light up, but it cannot detect a flame to keep the fire burning.
Your boiler has detected a false flame signal when the burner is not actually supposed to be lit, so it has safely locked out to prevent any risk.
Your boiler was running, but the flame went out unexpectedly, causing it to stop heating.
Your boiler has temporarily stopped working because an external safety switch, such as a smart thermostat or underfloor heating control, has locked the system.
Your boiler's internal computer is having trouble recognising a core internal part, so it has safely shut down to prevent any issues.
Your boiler has detected an electrical problem with the component that controls the gas supply, meaning it has safely shut down to prevent unsafe operation.
Your boiler is confused because its internal computer board and its identification settings do not match up correctly.
Your boiler has detected an internal system communication error and has safely shut down to prevent further issues.
Your boiler has detected an internal electronic failure within its main control system and has safely stopped working.
Your boiler has detected an internal electrical problem with its control system, which requires professional attention to resolve safely.
Your boiler has detected an internal electronic communication error and has safely shut down to protect its system.
Your boiler has temporarily paused because an internal reading has gone outside of its normal operating limits.
Your boiler's internal computer is experiencing a communication error and cannot safely manage the heating or hot water systems.
Your boiler's internal computer is experiencing a communication error or technical failure, preventing it from operating correctly.
Your boiler's computer is experiencing a temporary processing glitch that is preventing it from starting up correctly.
Your boiler has detected an internal computer glitch and needs to be reset or inspected by a professional.
Your boiler's computer has encountered an internal error and needs a reset or a service technician to investigate the control system.
Your boiler's internal computer has detected a serious communication failure during its safety check, preventing it from starting up safely.
Your boiler's internal computer is experiencing a software memory error, preventing it from operating correctly.
Your boiler's internal computer is experiencing a memory error and cannot safely operate the system.
Your boiler's internal computer is experiencing a memory error, meaning it has lost its stored settings and cannot safely manage its operations.
Your boiler's internal computer is experiencing a communication error and has decided to shut down to prevent potential damage.
Your boiler's main control computer is experiencing a temporary glitch or internal error, which has caused it to pause its normal operation as a safety precaution.
Your boiler's internal computer is experiencing a temporary software glitch and has shut down to prevent any unsafe operation.
Your boiler has detected an internal communication error with its main control unit that is preventing it from operating correctly.
The boiler's internal computer is experiencing a temporary software glitch and cannot properly communicate with its internal systems.
Your boiler's computer is having trouble starting up its internal system properly, which is preventing it from firing up.
Your boiler is struggling to breathe properly, meaning it cannot safely clear exhaust gases and has shut down to protect your home.
Your boiler is temporarily turning itself off because your radiators or taps aren't taking away the heat as fast as the boiler is producing it, often due to poor water flow.
Your boiler has detected an internal communication glitch during its self-test phase, which prevents it from firing up safely.
Your boiler has detected that the flame is not burning as it should and has shut itself down to keep your home safe.
Your boiler is currently just going through its automatic startup process and is not experiencing a fault.
Your boiler has detected that the flame-making process has stopped, preventing your heating or hot water from working.
Your boiler has accidentally been left in a restricted diagnostic mode used by engineers during installation, meaning it cannot currently heat your home or water.
Your boiler is struggling to push water through your heating system because the water pressure inside is too low.
Your boiler is currently going through its normal ignition sequence to fire up and provide heat or hot water.
Your boiler is having trouble managing the balance of air and gas required for safe combustion and has locked itself out to prevent potential issues.
Your boiler is temporarily pausing the hot water production to prevent itself from overheating or cycling on and off too frequently.
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's internal computer is failing to communicate correctly with its external controls, preventing your heating or hot water from turning on.
Your boiler has briefly lost power, likely due to a minor power cut or a loose plug connection.
Your boiler is temporarily shutting down because the water inside is heating up much faster than normal, usually due to a temporary blockage or restricted flow.
Your boiler is heating the water much faster than it is able to move it away, causing the system to stop as a safety precaution to prevent overheating.
Your boiler has lost its ability to accurately measure the temperature of the water flowing through the heating system because one of its internal sensors is sending a faulty electrical signal.
Your boiler has temporarily stopped working because it cannot properly read the temperature of the water flowing through it due to a sensor connection issue.
Your boiler is undergoing a factory test mode or internal diagnostic check and has temporarily paused its normal operation.
Your boiler has detected an internal software or safety check failure and has shut down to prevent unsafe operation.
Your boiler is struggling because the electricity supply it is receiving is weaker than it needs to operate reliably.
Your boiler is currently running a brief automatic test to clear any lingering gases from the internal system before it attempts to fire up again.
Your boiler is automatically running a short maintenance cycle to prevent its internal pump from getting stuck while it's not currently being used.
Your boiler's internal computer chip is not communicating correctly with its main control board, which prevents the unit from starting safely.
Your boiler's computer is having trouble communicating with its internal memory, which prevents it from safely operating your heating and hot water.
Your boiler has detected that the flame is remaining active when it should have shut off, preventing it from starting safely.
Your boiler has detected that an internal valve responsible for controlling gas flow is not closing correctly, meaning it is unsafe to continue operating.
Your boiler has detected an internal gas valve fault, meaning it can no longer safely manage the flow of fuel to the burner, so it has shut down to protect your home.
Your boiler has detected an internal communication error and has safely shut itself down to prevent it from operating incorrectly.
Your boiler is failing to detect or trigger the heating process required to provide you with hot water.
Your boiler's electronic control system is failing to communicate with its internal components, meaning the boiler has stopped working to protect itself.
Your boiler has detected that the burner is running at its maximum capacity for too long, causing it to proactively shut down to prevent overheating.
Your boiler is struggling to detect the flame needed to heat your water and has switched itself off for safety reasons.
Your boiler is simply reminding you that it is due for its annual safety service.
Your boiler has identified that the internal water pump is not the correct type for this specific model, which is preventing the system from operating correctly.
Your boiler is struggling to accurately detect the temperature of your hot water, which means it may fail to heat your water or work inconsistently.
Your boiler has been running for a very long period without a break and has automatically paused to prevent overheating.
Your boiler is struggling to accurately monitor the temperature of the water returning to it, so it has stopped working to prevent potential overheating.
Your boiler has lost the connection to the weather sensor outside your home and is now running on a default setting to ensure you still have heating and hot water.
Your boiler's internal sensor system is confused about the air quality or external temperature, which may hinder its efficiency or ability to run.
Your boiler has detected a faulty electrical signal regarding how hot the water is inside the system and has stopped working to prevent damage.
Your boiler has lost the ability to measure the temperature of the water inside it, so it has safely shut itself down to prevent overheating.
Your boiler has detected an electrical fault with the sensor that tracks the temperature of the water inside it, causing it to stop working to stay safe.
Your boiler has lost communication with its internal temperature sensor, so it has safely shut down to prevent overheating.
Your boiler's computer has detected a serious internal processing error that is preventing it from operating safely.
Your boiler has detected an internal software or electronic communication error that prevents it from operating safely.
Your boiler's main control computer is experiencing an internal error and cannot operate safely, meaning your heating and hot water will not work.
Your boiler's internal computer is experiencing a communication error and has shut down for safety to prevent incorrect operation.
Your boiler has detected an issue with the pipework that vents exhaust gases outside, meaning it has safely shut itself down to prevent any harmful fumes building up indoors.
Your boiler's internal computer has failed to automatically adjust its settings to ensure it burns gas safely and efficiently.
Your boiler is struggling to start the internal fire necessary to produce heat, meaning it has safely shut itself down to prevent gas from building up.
Your boiler is struggling to detect the flame accurately while it tries to set itself up, meaning it cannot safely start your heating or hot water.
Your boiler's internal computer is failing to talk to the part that creates heat, meaning it cannot start up.
Your boiler's ventilation fan is continuing to run long after it should have finished cooling down, which often indicates an internal electronic fault.
Your boiler has detected that the internal gas valve failed to close properly after it finished its last cycle, which could pose a safety risk.
Your boiler is failing to light the internal flame needed to heat your home's water.
Your boiler has detected an issue with the way it is burning gas and has shut itself down to ensure your safety.
Your boiler has detected a problem with how it tracks its own flame, causing it to shut down for safety purposes.
Your boiler is currently stuck in a diagnostic testing mode used by engineers rather than operating in its normal heating mode.
Your boiler has encountered an internal electronic error that is preventing it from operating correctly.
Your boiler has detected an issue with the valve that controls the gas supply, meaning it has safely shut itself down to prevent any risk.
Your boiler has detected an issue with the fuel supply system, meaning it cannot confirm that gas is flowing correctly, so it has safely shut itself down.
Your boiler is struggling to control the gas flow needed to heat your home, so it has safely shut itself down to prevent any issues.
Your boiler has detected an issue with the control system that regulates the gas flow, meaning it has switched itself off to stay safe and is currently unable to provide heating or hot water.
Your boiler has stopped working because the flame inside went out while it was trying to heat your water or home.
Your boiler has detected a communication error between its internal electronic brains, causing it to shut down for safety.
Your boiler has detected an internal electronic or controller glitch that is preventing it from running safely and normally.
The internal computer in your boiler has encountered a major software error and has stopped operating to prevent further damage.
Your boiler's internal computer is experiencing a communication error, meaning it has safely shut down to prevent incorrect operation.
Your boiler's electronic control system is not receiving the correct amount of electrical power, preventing it from starting safely.
Your boiler is struggling to pump enough water through the system, meaning it cannot heat your home or provide hot water effectively.
Your boiler has stopped working because it cannot detect that the internal fan, which is essential for safely venting exhaust gases, is spinning correctly.
Your boiler is struggling to work because the electricity supply it is receiving from your home's wall socket is weaker than it needs to be.
Your boiler is rapidly cycling on and off because it cannot efficiently release the heat it is generating, which often points to a blockage or a bottleneck in your heating system.
Your boiler's computer memory chip is not being recognised or is mismatched, which prevents the system from starting up.
Your boiler's computer chip is not communicating correctly with the main control board, which is preventing the system from starting up safely.
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 has attempted to ignite several times but is failing to stay lit, so it has shut down as a safety precaution.
Your boiler has tried to start up but cannot detect a flame, meaning it cannot provide heating or hot water.
Your boiler is repeatedly trying to stay lit but failing, which means it will stop working to keep you safe.
Your boiler is having trouble confirming that the burner is lit safely, so it has stopped working to prevent any potential risks.
Your boiler has attempted to start but failed to detect a flame, meaning it cannot produce heat or hot water.
Your boiler has attempted to ignite several times but is failing to stay lit, meaning you currently have no heating or hot water.
Your boiler has detected that its internal settings do not match the way your heating system is physically set up, meaning it cannot safely start until these are corrected.
Your boiler has detected that a specific accessory or additional part has been connected and needs to be set up through the control panel.
Your boiler has detected an internal fault within its computer brain that prevents it from safely lighting the flame.
Your boiler's internal computer is experiencing a communication error or failure and is unable to operate safely.
Your boiler's internal computer is experiencing a software or communication error and has safely shut itself down to prevent further issues.
Your boiler's main control computer is experiencing a communication or internal processing error, causing it to shut down to prevent damage.
Your boiler is unable to detect that its internal air fan is spinning, so it has safely shut itself down to prevent operation without proper ventilation.
Your boiler has stopped working because the internal component responsible for clearing exhaust gases is not spinning, which prevents the unit from firing up safely.
Your boiler has detected an incorrect temperature reading, which has caused it to shut down for safety reasons to prevent overheating.
Your boiler is struggling to pump water through its internal system effectively, which is likely preventing it from producing heat or hot water.
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 is overheating too quickly because water isn't moving through the system fast enough.
Your boiler has detected that the water temperature at different points inside the unit does not match up correctly, causing it to shut down to prevent damage.
Your boiler is struggling to work because the electricity supply coming from your home's wall socket or wiring is weaker than it needs to be.
Your boiler’s internal computer is experiencing a communication error or software glitch that is preventing it from operating correctly.
Your boiler's computer is experiencing an internal error and cannot operate correctly, which means you currently have no heating or hot water.
Your boiler has lost wireless communication with its thermostat controller, meaning it cannot properly receive instructions to turn on your heating.
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BoilerFaultCodes