137 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has lost the ability for its internal electronic components to talk to each other, so it has shut down to prevent incorrect operation.
Your boiler is simply displaying its current power setting and is operating normally.
Your boiler is currently running its internal pump to circulate residual heat, which is a normal part of the system's cooling process.
This is a normal operational setting, not a fault; it simply indicates the boiler is timing out between heating cycles to prevent excessive wear.
Your boiler is simply displaying the current temperature reading from the hot water storage tank sensor.
Your boiler is simply displaying a live status update showing the temperature it is currently aiming to reach for your radiators.
This code is simply an information display showing the current temperature setting for your hot water, rather than indicating a fault.
Your boiler is simply displaying the current temperature setting for your hot water cylinder as part of its normal operation.
This code is simply an information display showing the current signal from your wall thermostat, letting you know if your heating is correctly receiving a request to turn on or off.
This code is simply a status message showing the temperature your thermostat is requesting, not an actual fault with your boiler.
Your boiler is simply displaying the current operating status of its internal water pump to let you know if it is switched on or off.
Your boiler is simply performing a routine check on its internal water pump to ensure heat is moving around your system correctly.
Your boiler is simply reporting that the internal pump responsible for moving water around the heating system is currently switched off.
This code is simply an information display showing the current speed setting of your heating system's water pump, rather than a sign of a fault.
This code is simply showing you the current operating speed of your boiler's internal water pump and is not an error message.
Your boiler is currently receiving a signal from your thermostat telling it to stay off, so it is simply waiting for a command to start heating.
Your boiler is currently set to monitor the warmth of the water returning to it rather than the water leaving it, which is a specific setting typically used for underfloor heating systems.
This is just an information code showing how your boiler's internal water pump is currently set to behave, which is normal operation rather than a system error.
This code is simply an information display showing the current operating setting of your boiler's internal pump, rather than an error or fault.
This code indicates that your boiler is currently working within its normal temperature settings for your hot water and does not represent a system fault.
This code is simply an information message telling you whether your boiler's 'fast hot water' feature is currently turned on or off, rather than signaling a fault.
Your boiler is currently monitoring your hot water system and is simply indicating that no hot water is being requested at this moment.
Your boiler is currently operating normally and is simply indicating that no heating is required at this moment.
Your boiler is signalling that the water pressure is either too low or the sensor monitoring the flow is not detecting any movement, which usually prevents the unit from starting.
This code is simply an information message indicating that your hot water cylinder or 'warm start' feature is currently switched off or not being requested by your thermostat.
This code is simply an information display showing how your boiler's extra electrical port is currently configured to control external equipment, rather than indicating a fault.
This code is not a fault, but rather a status display showing how your boiler is configured to control external add-ons like pumps or valves.
This code is simply an information display showing the current configuration mode of your boiler's automated water pressure system rather than indicating a fault.
Your boiler is currently monitoring the speed of its internal air intake fan to ensure it is operating at the correct level for safe combustion.
This code is simply showing you the current operating speed of your boiler's internal fan, rather than indicating a fault.
Your boiler is currently monitoring or moving the internal switch that directs hot water to either your radiators or your taps.
This code is simply showing you a live reading of how much hot water is flowing through your system, rather than indicating a fault.
Your boiler is simply reporting the current temperature reading from your solar heating system, which is a routine data check rather than a system error.
This code is simply showing you the current temperature of the water flowing through your heating system and is not an error message.
Your boiler is simply reporting the current temperature of the water returning to it from your radiators.
This code is simply an information display showing the current heater setting level, not an error or a sign that your boiler is broken.
Your boiler is displaying a status code indicating that a internal heating temperature setting has been adjusted to a value outside of its normal operating range.
Your boiler is simply displaying the current temperature being read from an outdoor weather sensor connected to your system.
Your boiler is currently running a calibration routine to adjust its internal air supply settings to meet efficiency standards.
Your boiler has detected that the internal fan is running outside of its normal speed range, which is preventing it from heating your home safely.
Your boiler is notifying you about its settings for how it handles solar-heated water and safety checks for bacteria in your storage tank.
Your boiler has safety-stopped itself several times because it detected the water getting too hot, indicating a possible issue with the system's ability to circulate water properly.
Your boiler has failed to start up several times in a row and is currently preventing itself from trying again to ensure safety.
This code is simply an information display showing the current temperature setting for your heating during the night, rather than an error or fault with the boiler's operation.
This code is simply an information display showing the average time it takes for your boiler to ignite, rather than a sign that something is broken.
This code is simply a background status display showing how many seconds the boiler took to ignite during its most recent start-up attempt.
This code simply indicates whether the comfort setting that keeps your tap water pre-warmed is currently turned on or off.
Your boiler is currently in a brief, normal cooling-down period and will restart automatically once this timer finishes.
Your boiler has struggled to light on its first try multiple times, which acts as a log to help engineers track recurrent ignition issues.
Your boiler has failed to light the burner multiple times and is currently recording these failed attempts.
Your boiler is undergoing a diagnostic check on the valve that directs hot water, which is a standard procedure rather than a breakdown.
Your boiler has lost the signal from the sensor that monitors how hot the water is, meaning it has safely shut itself down to prevent overheating.
Your boiler has lost the signal from one of its internal heat sensors, meaning it cannot accurately monitor the temperature of the water returning to the system and has shut down as a precaution.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water flowing through it, likely due to a faulty sensor or a loose electrical connection.
Your boiler has detected a faulty connection to the sensor that monitors the temperature of the water returning to the system, causing it to stop operating as a safety precaution.
Your boiler has lost the connection to the temperature sensor in your hot water tank, meaning it currently doesn't know when the water has finished heating up.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Your boiler has detected that the water is getting much hotter in one part of the system than the other, causing it to shut down to prevent internal damage.
Your boiler is shutting down because it detects that the water inside is heating up much faster than it should, which suggests the water cannot circulate properly.
Your boiler has detected that the exhaust gases are becoming dangerously hot and has shut itself down to prevent damage or overheating.
Your boiler has detected a signal that suggests a flame is present even when the boiler is switched off, so it has stopped working as a safety precaution.
Your boiler is attempting to start but cannot successfully light the flame to provide heating or hot water.
Your boiler is trying to start up but is failing to stay lit, which means it cannot produce heat or hot water.
Your boiler has detected that the internal components responsible for venting waste gases are not spinning correctly, so it has purposefully shut itself down for safety.
Your boiler has detected an issue with its airflow system, meaning it cannot safely vent exhaust gases, so it has shut down to prevent a fire or carbon monoxide risk.
Your boiler is having trouble communicating with its external controls like the thermostat or timer, usually due to a loose wire or a power issue in the connection cable.
Your boiler has detected an internal electrical problem that is preventing it from safely controlling the gas supply, so it has shut down to protect your home.
Your boiler has detected that the gas supply is not turning off correctly when it should, so it has safely shut itself down to prevent any risk.
Your boiler's computer memory has experienced a critical error, meaning it can no longer safely operate or process its internal instructions.
Your boiler's computer is struggling to read data from its internal sensors, meaning it has switched itself off to prevent a malfunction.
Your boiler has detected that its internal computer is getting too hot, so it has safely shut itself down to prevent damage to its electronic components.
Your boiler has detected an internal communication error with its flame-monitoring system, meaning it cannot safely confirm that the burner is operating, so it has shut down to prevent any risk.
Your boiler is struggling to keep its internal flame lit steadily, so it has turned itself off to stay safe.
Your boiler's computer has lost its identity settings and cannot communicate correctly with the internal parts, meaning it has shut down for safety.
Your boiler is struggling because a temperature sensor is sending inconsistent signals, causing it to block its own operation to play it safe.
Your boiler has lost the ability to accurately measure the temperature of the water flowing through it, so it has purposefully shut down to prevent overheating.
Your boiler is struggling to detect the water pressure inside the system because the sensor is providing an incorrect reading.
Your boiler's internal water pressure gauge is reporting an inaccurate or impossible reading, which is preventing it from starting safely.
Your boiler is struggling to confirm that water is moving through the system, meaning it will likely shut down to prevent itself from overheating.
Your boiler has detected that it is running too hot and has safely shut itself down to prevent damage to its internal components.
Your boiler has detected an issue with the system responsible for removing exhaust gases or draining away the water produced during the heating process.
Your boiler is having trouble communicating with the external controls meant to manage your hot water cylinder.
Your boiler is struggling to accurately measure how hot the water is as it moves around your heating system, so it has shut down to prevent overheating.
Your boiler has detected an inconsistent temperature reading between the pipes, suggesting it is struggling to accurately measure how well water is circulating through your heating system.
Your boiler has detected that a temperature sensor is not fitted correctly, meaning it cannot accurately measure the heat and has shut down to protect the system.
Your boiler has detected that the external sensor monitoring your underfloor heating system is not communicating correctly, meaning your underfloor heating may not turn on or regulate its temperature properly.
Your boiler is failing to light the flame properly because there is a communication issue with the part responsible for ignition.
Your boiler has detected an issue with the assembly that controls the supply of gas to the burner, meaning it cannot safely ignite to provide heating or hot water.
Your boiler has detected that the internal water pump is not running correctly, which stops the system from circulating heat to your radiators or hot water tank.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Your boiler is currently running a 15-minute automatic cycle to clear trapped air out of your heating system pipes.
Your boiler is currently performing an automatic internal air-clearing routine to help remove trapped air from the system.
Your boiler is perfectly healthy and is simply waiting for a signal from your thermostat or timer to start heating your home or water.
Your boiler is currently just running a routine safety check on its internal fan before starting to heat your home.
Your boiler is simply preparing to send hot water around your radiators and is currently checking the water flow.
Your boiler is currently working correctly and is in the process of lighting the flame to begin heating your home.
Your boiler is operating exactly as it should and is currently actively heating your radiators.
Your boiler is currently cooling itself down after being in use, which is a normal part of its automatic shut-down process.
Your boiler is currently just running its fan to clear out any leftover gasses after it finished heating, and this is a completely normal part of its shutdown process.
Your boiler is perfectly fine; this isn't an error code, but simply a status message letting you know the system is moving warm water through your pipes after the heating has turned off to make the most of the remaining heat.
Your boiler has currently paused its heating cycle to allow its internal temperature to balance out before restarting.
Your boiler is simply performing its normal job of preparing to heat your hot water or radiators.
Your boiler is simply performing a routine safety check by clearing its internal ventilation before it begins heating your water.
Your boiler is currently just attempting to light its burner to start heating your water.
Your boiler is operating normally and is currently busy heating up your hot water.
Your boiler is simply finishing a cooling cycle after providing hot water and will resume normal operation shortly.
Your boiler is currently running its internal fan to clear out any leftover heat after you have finished using hot water.
Your boiler is simply finishing a safety cooling cycle after heating your water and is performing exactly as it should.
Your boiler is currently operating normally as it is in the process of heating your hot water.
Your boiler is simply preparing to heat your home or water by clearing out the internal airflow before starting up.
Your boiler is simply preparing its internal pump to begin heating your hot water, which is a normal part of its startup sequence.
Your boiler is currently just starting the process to heat water for your taps or radiators.
Your boiler is currently working correctly and is heating up your hot water.
Your boiler is simply finishing its cooling process after heating your water, which is a normal part of its internal operation.
Your boiler is currently cooling down its internal components after finishing a hot water task, which is a normal part of its shutdown process.
Your boiler is currently shifting leftover heat away from the hot water system to prevent internal overheating, which is a normal part of its cooling process.
Your boiler has temporarily paused the burner while it adjusts the water temperature, which is a normal part of its internal operating process.
Your boiler is currently waiting for a signal from your thermostat to turn the heating on, so it is just sitting in standby mode.
Your boiler is currently in standby mode because it has not been asked to provide any heating or hot water, so it is simply waiting for a signal from your thermostat.
Your boiler is pausing during startup because the internal fan is not spinning at the exact speed requested by the safety controls.
Your boiler is temporarily waiting for its internal air pressure system to reset before it can safely start the ignition process.
Your boiler has detected that the temperature is low and has briefly activated its internal heating to prevent the pipes from freezing.
Your boiler is temporarily pausing because the external switch that monitors your underfloor heating system is currently signaling that the circuit is in the off position.
Your boiler's internal water pressure is currently higher than the recommended limit, which may cause it to stop working to protect the system.
Your boiler has detected that the flap which prevents exhaust gases from flowing back into the system is stuck shut, meaning it cannot safely release gasses outside.
Your boiler is temporarily limiting its power output to protect itself while it adjusts to the current demand from your heating system.
Your boiler has temporarily stopped because it cannot circulate water efficiently, likely due to low pressure or an obstruction preventing heat from moving around the system.
Your boiler has temporarily stopped because it has detected that the water pressure is too low to circulate heat safely.
Your boiler is currently running a routine 'self-bleeding' cycle to clear trapped air from the system, which is a normal process that happens automatically.
Your boiler has been accidentally set to a factory demonstration mode, which disables the heating and hot water functions until it is adjusted back to normal operation.
Your boiler is currently running a brief internal self-check and has temporarily paused your heating and hot water to complete it.
Your boiler is currently performing a brief automatic system check, which is temporarily pausing your heating and hot water.
Your boiler is currently running a self-diagnostic check, which is temporarily pausing your heating and hot water.
Your boiler is currently refilling its internal water pressure system automatically, which is a normal process intended to keep your heating running smoothly.
Your boiler is currently performing a standard safety check to clear out the combustion chamber before it starts heating up.
Your boiler is currently in a temporary power-saving standby mode and is working exactly as intended.
BoilerFaultCodes