23 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is receiving an incorrect reading from the sensor that monitors the air temperature outside, which may cause your heating system to run less efficiently.
Your boiler has lost the connection to the thermometer on the outside of your house, but it should still continue to keep your home warm in the meantime.
Your boiler's temperature sensor is reporting an electrical fault, meaning the system cannot accurately measure how hot the water is, so it has shut down as a safety precaution.
Your boiler has stopped working because it has lost the electrical signal from the main water temperature sensor.
Your boiler is failing to detect a request for hot water from your cylinder, which usually means your hot water temporarily won't heat up.
Your boiler is not communicating properly with your hot water cylinder, which usually means your radiators work fine but your hot water stops heating up.
Your boiler has temporarily stopped working because it has detected an electrical wiring issue with one of its internal temperature sensors.
Your boiler has temporarily stopped working because it cannot properly read the temperature of the water returning from your radiators.
Your boiler is having trouble communicating with its external control panel or thermostat.
Your boiler has detected an electrical fault in the sensor that monitors the temperature of the gases leaving your flue, meaning the boiler has safely shut down to prevent potential damage.
Your boiler has temporarily stopped working because it cannot properly read the temperature of the gases leaving the flue.
Your boiler has detected an internal electronic error that is preventing it from starting safely.
Your boiler has detected an internal electronic error that is preventing it from starting up correctly.
Your boiler has detected that the exhaust gases are becoming dangerously hot and has shut itself down to prevent damage or fire risk.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler has detected that a flame is present before it has actually been told to start, which prevents it from safely igniting.
Your boiler has failed to ignite its burner, meaning it is currently unable to provide heating or hot water.
Your boiler has safely shut off its gas supply because it detected an issue with the gas valve or the way it is communicating.
Your boiler is locking out because it cannot detect that the internal fan is spinning up properly to safely clear combustion gases.
Your boiler has detected that the internal fan is still spinning when it should be switched off, which prevents the system from starting up safely.
Your boiler has detected an internal communication error with the internal fan, which means it will stop working to ensure your safety.
Your boiler's internal computer has detected a fault with the control system that manages the burner, preventing it from heating your home or water.
Your boiler's main electronic brain has encountered an internal error and stopped working to keep your home safe.
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BoilerFaultCodes