133 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected an issue with the flame flame-sensing mechanism or the exhaust gases, and has safely locked out to prevent unsafe operation.
Your boiler has stopped working because the water pressure inside your heating system is too low.
Your boiler's internal clock has lost its memory because a small backup battery has run out of power.
Your boiler has detected that waste water is backing up inside the main heating unit, which is preventing it from running safely.
Your boiler is simply notifying you that it was unable to set a reminder for its next scheduled service.
Your central heating system currently has too much water inside it, causing the internal pressure to rise above the safe limit.
Your boiler has stopped working because it cannot correctly measure the temperature of the water leaving the unit due to a sensor or wiring fault.
Your boiler is currently unable to heat your domestic hot water, meaning you will not have any hot water available from your taps or shower.
Your boiler is currently unable to heat your domestic hot water, meaning you will not have hot water available from your taps or shower.
Your boiler has lost connection with the sensor that monitors your hot water temperature, which usually means it cannot heat your water safely or at all.
Your boiler has identified a technical fault with the sensor that monitors your hot water temperature, which typically means you will not have reliable hot water.
Your boiler is not detecting heat coming from your solar thermal panels, so it cannot use that energy to help warm your home or water.
Your boiler has detected that the solar thermal panels connected to your heating system are not currently producing hot water as expected.
Your boiler has lost its connection to the sensor that measures the temperature outside, meaning it may not know how hard it needs to work to heat your home.
Your boiler is struggling to work out how hard to run because its external weather thermometer has developed an electrical fault.
Your boiler has lost the ability to communicate with or receive heat from your solar thermal panels, meaning it cannot use free energy from the sun to help heat your water.
Your boiler is reporting that it is not receiving heat from your solar thermal panels to warm your hot water tank as expected.
Your boiler has lost communication with a sensor that monitors the water temperature in your heating system's distribution hub.
Your boiler has detected a technical fault with a sensor that monitors water temperature elsewhere in your heating system, which is preventing the boiler from running correctly.
Your boiler has detected a persistent issue with the burner and has automatically shut itself down to prevent unsafe operation.
Your boiler has detected an internal issue and has safely shut itself down to prevent damage, meaning you currently have no heating or hot water.
Your boiler is currently ignoring the temperature settings from your wall thermostat and is running based solely on the weather outside or its own internal default settings.
Your boiler is operating in a basic mode because it has lost the signal from your room thermostat, meaning it cannot adjust its temperature based on how warm your home is.
Your boiler has stopped working because it isn't receiving enough electrical power to operate the burner safely.
Your boiler has detected an internal error during the ignition process and has safely shut down to prevent it from firing improperly.
Your boiler has detected a critical internal error in its main electronic control unit, causing it to shut down to prevent unsafe operation.
Your boiler has detected an internal issue with the burner flame signal, causing it to shut down for safety reasons to prevent improper combustion.
Your boiler has detected an issue with the flame stability or air-gas supply and has shut down for safety.
Your boiler has detected an internal issue and shut itself down as a safety precaution, meaning you currently have no heating or hot water.
Your boiler's electronic control unit is experiencing an internal error and has safely shut down the system to prevent further issues.
Your boiler has detected an internal issue with its temperature monitoring system and has automatically shut down to prevent damage.
Your boiler has detected an issue with the temperature sensors that monitor the heating process, causing it to shut down for safety.
Your boiler has detected an internal issue with the water pressure sensor, which is preventing it from safely lighting the burner.
Your boiler has detected that the water pressure in the system is too low to operate safely, causing it to shut down to prevent damage.
Your boiler's internal computer brain is having trouble reading or saving its settings, causing the system to stop working for safety.
Your boiler has detected an internal communication error between its main control components, causing it to shut down for safety.
Your boiler has detected an issue with an external accessory or control module and is running in a limited backup mode to keep you warm until it can be properly checked.
Your boiler's internal computer brain is struggling to talk to one of its electronic control parts, causing the system to stop working.
Your boiler's internal computer parts have stopped communicating with each other, preventing the system from operating correctly.
Your boiler has stopped working because of a communication failure between its internal electronic parts, meaning the main controls can no longer talk to each other.
Your boiler has detected an error with an external electronic add-on, meaning it is unsure how to control certain heating or hot water features.
Your boiler has detected an internal issue and has safely shut itself down to prevent damage, meaning you currently have no heating or hot water.
Your boiler has detected an issue preventing it from lighting the flame, which means your heating and hot water have stopped working.
Your boiler has detected an issue with the burning process and has shut itself down to keep your home safe.
Your boiler has detected an issue with the burner process and has shut itself down as a safety precaution to prevent further faults.
Your boiler is currently unable to heat your domestic hot water, meaning you will likely have no hot water coming out of your taps.
Your boiler has stopped heating your hot water supply, meaning your taps and shower will only run cold.
Your boiler has detected an internal error preventing the burner from lighting, which means your heating and hot water will not work until the fault is cleared.
Your boiler has detected an internal error preventing the burner from lighting, which means your heating and hot water will not work until the fault is cleared.
Your boiler has lost its internal time and date settings, which may disrupt your heating schedules.
Your boiler has detected an internal communication error between its main control components, causing it to shut down for safety.
Your boiler has automatically shut down because it has detected that the internal water temperature has become dangerously high.
Your boiler has detected an internal issue and has safely shut itself down to prevent operation while it is not functioning correctly.
Your boiler has detected an issue with the internal combustion process and has safely shut itself down to prevent unsafe operation.
Your boiler has detected a problem with the burner operation and has automatically shut itself down for safety reasons.
Your boiler has detected an internal issue and has safely shut itself down to prevent damage, meaning you currently have no heating or hot water.
Your boiler has detected an internal issue and has safely shut itself down to prevent any potential safety hazards.
Your boiler has detected an issue with the burner ignition or combustion process and has shut itself down as a safety precaution.
Your boiler has detected a minor inconsistency in the internal combustion process and is temporarily pausing to restart safely.
Your boiler has detected an issue that prevents the burner from igniting, meaning your heating and hot water will not work until this is cleared.
Your boiler has detected a flame before it has even started the ignition process, which is a safety conflict that prevents the system from running.
Your boiler has detected an internal issue and has safely shut itself down to prevent further problems.
Your boiler has detected an internal issue and has safely shut down the burner to prevent further problems.
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 detected that the burner is not firing correctly, which has caused it to stop working to prevent any potential safety issues.
Your boiler has stopped working because it failed to light or maintain a flame correctly, so it has shut itself down for safety reasons.
Your boiler has detected an issue with the burning process and has automatically shut down to keep your home safe.
Your boiler has detected an internal issue with the combustion system and has safely shut itself down to prevent damage or safety hazards.
Your boiler has detected a general issue preventing it from firing up, which means you currently have no central heating or hot water.
Your boiler has detected an issue with the burner preventing it from firing, meaning your heating and hot water will not be working.
Your boiler has detected an internal issue and has safely shut down the burner to prevent damage, meaning you currently have no heating or hot water.
Your boiler has detected an internal issue and has safely shut itself down to prevent damage, meaning you currently have no heating or hot water.
Your boiler has detected an internal issue with the combustion process and has stopped working to keep your home safe.
Your boiler has detected an issue with the internal combustion process and has safely shut itself down to prevent any further problems.
Your boiler has detected a general issue with its internal combustion process and has safely shut itself down to prevent potential damage.
Your boiler has detected a general issue within the burner system and has automatically shut down to prevent further problems.
Your boiler has detected a problem with the burner's operation and has safely shut itself down to prevent potential issues.
Your boiler has detected an internal issue that is preventing the burner from igniting, meaning you currently have no heating or hot water.
Your boiler has detected an internal issue and has safely shut itself down to prevent any potential risks.
Your boiler has detected an internal issue and has shut itself down as a safety precaution to prevent damage.
Your boiler has detected an internal issue and has safely shut itself down to prevent potential damage, meaning you currently have no heating or hot water.
Your boiler has detected an internal issue that is preventing the burner from igniting, meaning your heating and hot water will not work until the fault is cleared.
Your boiler has detected a general issue with the burner and has safely shut itself down to prevent further problems.
Your boiler has detected an issue with the burner and has safely shut itself down to prevent potential damage or unsafe operation.
Your boiler has detected an issue with the burner process and has shut itself down as a safety precaution to prevent unsafe operation.
Your boiler has detected an internal error preventing the burner from lighting, which means your heating and hot water will not work until the fault is cleared.
Your boiler has detected a general issue with the burner's operation and has safely shut itself down to prevent further problems.
Your boiler has stopped heating because the burner has detected a safety fault and shut itself down to prevent any damage.
Your boiler has detected an issue with the burning process and has automatically shut down for safety reasons to prevent it from operating incorrectly.
Your boiler has detected an internal issue with the burner and has safely shut itself down to prevent further problems.
Your boiler has detected an issue with the combustion process and has safely shut down to prevent unsafe operation.
Your boiler has detected an issue with the combustion process and has safely shut itself down to prevent it from running incorrectly.
Your boiler has detected an issue with the burner process and has shut down to keep your home safe.
Your boiler has detected an internal issue that is preventing it from lighting safely, so it has shut down to protect your home.
Your boiler's main internal computer has encountered a critical processing error and can no longer control the burner safely.
Your boiler has shut down because it detects that a safety sensor meant to monitor exhaust fumes is loose or installed incorrectly.
Your boiler has detected an internal issue and has automatically shut itself down for safety reasons to prevent further damage.
Your boiler has stopped working because its internal computer has lost power or has a broken electrical connection.
Your boiler's internal computer is having difficulty processing its programmed settings, causing it to pause operations to prevent incorrect function.
Your boiler is currently operating normally under automated control settings, and this code is simply a status message confirming it is working as expected.
Your boiler has detected an issue with the burner's ability to stay lit or ignite correctly and has shut down for your safety.
Your boiler has detected an internal error that has forced it to stop heating to ensure your home remains safe.
Your boiler has detected an issue with the combustion process or burner ignition and has safely shut itself down to prevent further problems.
Your boiler has detected an issue with the burning process and has automatically shut itself down for safety reasons.
Your boiler has detected an issue with the burner's operation and has safely shut itself down to prevent potential damage.
Your boiler has detected an issue with the combustion process and has safely shut down to prevent it from running incorrectly.
Your boiler has detected an issue with the burner process and has shut itself down as a safety precaution to prevent further faults.
Your boiler has detected a persistent issue with the combustion process and has safely shut itself down to prevent unsafe operation.
Your boiler has detected an internal issue with the burner and has safely shut itself down to prevent operation while it is not functioning correctly.
Your boiler has detected an internal issue with the burner and has safely shut itself down to prevent further problems.
Your boiler has detected an issue with the combustion process and has safely shut itself down to prevent unsafe operation.
Your boiler has stopped working because it has detected an internal issue and triggered a safety shutdown to prevent further problems.
Your boiler has stopped working because it has detected an internal issue and shut itself down for safety reasons.
Your boiler has detected a general issue within its internal combustion system and has safely shut itself down to prevent further damage.
Your boiler has detected an issue with the burner's operation and has safely shut itself down to prevent potential problems.
Your boiler has detected an issue with the burner process and has shut itself down as a safety precaution to prevent further faults.
Your boiler has detected an issue with the burner ignition or combustion process and has safely shut itself down to prevent further problems.
Your boiler has detected an issue with the burner and has safely shut itself down to prevent further problems.
Your boiler is currently idle because it is not receiving a signal from your thermostat or hot water controller to provide heat.
Your boiler is currently idle because it is not receiving a signal from your thermostat or heating controls to start producing heat.
Your boiler has detected an internal issue and shut down for safety to prevent damage, meaning you currently have no heating or hot water.
Your boiler is struggling to communicate with its external control panel or thermostat, which may prevent it from receiving instructions to turn on your heating or hot water.
Your boiler has detected an internal issue with the burner ignition process and has safely shut itself down to prevent any unsafe operation.
Your boiler has detected an issue with the combustion process and has safely shut itself down to prevent unsafe operation.
Your boiler has detected that the solar heating panels connected to your system are not operating at full efficiency.
Your boiler has detected an issue with the burner and has safely shut itself down to prevent unsafe operation.
Your boiler has detected an issue with the valve that regulates the temperature of your heating water, so it has shut that valve to protect your system while keeping the water pump running.
Your boiler has detected an issue with the valve that regulates your heating temperature, causing it to shut down to prevent the system from getting too hot.
Your boiler has detected that the mixing valve is not positioning correctly, which may lead to your radiators failing to reach the desired temperature.
Your boiler has detected that the valve controlling the water temperature to your radiators has closed, which means your heating may not get as warm as you have set it.
Your boiler has detected that the mixing valve is not operating correctly, which may lead to your radiators not reaching the desired temperature.
Your boiler has detected an issue with the valve that regulates your heating temperature, causing it to shut off to prevent water from becoming too hot.
Your boiler has been temporarily stopped by an external device, such as a smart thermostat or a safety switch, which is telling the system not to run.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes