43 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is struggling to light its internal flame properly, meaning it cannot reliably provide heating or hot water.
Your boiler has detected an electrical short-circuit in its internal wiring, which means it has safely shut itself down to prevent damage.
Your boiler is failing to light the internal burner, which means it cannot produce any heat or hot water.
Your boiler has experienced a power glitch or an issue with its internal electrical supply that has caused it to stop working.
Your boiler is currently stuck in an internal settings mode or has detected an issue with its basic operating parameters that requires a professional to recalibrate.
Your boiler has lost communication with the weather sensor outside your home and is now running on its default safety settings.
Your boiler has detected that the water inside the heating system is getting too hot too quickly, likely because the water is not circulating properly through your radiators.
Your boiler has stopped working because an internal safety fuse responsible for the control power has blown, preventing the system from operating.
Your boiler has detected that the water inside the system is getting much hotter than it should be and has shut down to prevent damage.
Your boiler has detected that the water returning to it from your radiators is getting too hot, so it has shut itself down to prevent damage.
Your boiler is struggling to detect the flow of water through its system, which means it cannot safely heat your home or provide hot water.
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 accurately read the temperature of the water returning to it, which prevents it from heating your home reliably.
Your boiler is having trouble detecting the temperature of the water coming from your taps, which means it cannot heat your hot water properly.
Your boiler has lost the correct settings that control its burning intensity, so it has safely stopped working to prevent damage.
Your boiler has detected an unusual temperature difference between its internal pipes while it is turned off, which may indicate a sensor error or a flow problem.
Your boiler's screen has gone blank or is showing incorrect information, meaning the system is currently unable to communicate or control your heating and hot water.
Your boiler has detected that the exhaust gases are becoming too hot, so it has automatically shut down to prevent damage to the internal components.
Your boiler has stopped working because it cannot detect the temperature of the exhaust gases, which is a safety measure to prevent it from operating incorrectly.
Your boiler has detected a faulty electrical signal from its exhaust temperature sensor, so it has safely shut down your heating and hot water to prevent damage.
Your boiler is struggling to detect water moving through the system and is automatically running a brief self-test to clear any trapped air.
Your boiler has detected that an external safety device, such as a heat sensor or chimney flue thermostat, has triggered a shutdown to prevent overheating or unsafe operation.
Your boiler has temporarily stopped heating your home because the water is not circulating fast enough to transfer heat away, likely due to a blockage in your pipes or radiators.
Your boiler has temporarily stopped heating your hot water because the temperature difference between the water leaving and returning to the boiler is too high, often caused by a blockage or flow issue.
Your boiler's internal settings have been incorrectly configured, preventing it from safely regulating its power output.
Your boiler has detected an unusual temperature difference inside the system while the heating is turned off, so it has paused its operation to prevent any potential damage.
Your boiler has automatically paused itself because the waste gases exiting the flue are dangerously hot, likely indicating an internal system blockage or a failed sensor.
Your boiler has detected that a critical safety sensor monitoring exhaust gases has become unplugged or disconnected, so it has safely shut itself down to prevent operation.
Your boiler has detected a faulty sensor reading in the exhaust system and has safely shut itself down to prevent it from running incorrectly.
Your boiler is temporarily pausing because it cannot detect enough water moving through the system and is attempting to clear any trapped air bubbles automatically.
Your boiler is struggling to light correctly or stay lit, which means it will not be able to provide heating or hot water until the issue is resolved.
Your boiler has detected an electrical short-circuit in its internal wiring, which has triggered an automatic safety shutdown to prevent further damage.
Your boiler is trying to start but cannot detect a flame, so it has safely shut down to prevent gas from building up.
Your boiler has detected a power issue or a software hiccup which has caused it to stop working for safety reasons.
Your boiler is struggling to calibrate itself correctly, which is preventing it from firing up reliably.
Your boiler has stopped working because a small protective fuse that powers the internal control system has blown.
Your boiler has detected that the water inside the system has become dangerously hot and has shut itself down to prevent damage or overheating.
Your boiler has shut down because the water returning from your radiators is too hot, which suggests an issue with how the water is flowing or being measured inside the system.
Your boiler's fan is failing to communicate with the control board, meaning the system cannot safely vent exhaust gases and has shut down to prevent potential danger.
Your boiler's electronic control panel is experiencing a communication error, meaning it cannot properly display information or talk to the main computer.
Your boiler has detected that the exhaust gases leaving your home are becoming dangerously hot and has shut itself down to prevent damage.
Your boiler has automatically stopped working because the water pressure inside your heating system has dropped too low.
Your boiler has detected that the water pressure inside your heating system is too high and has safely shut itself down to prevent damage.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes