17 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Flexicom CXI II
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Your boiler has detected an electrical fault in the sensor that monitors the temperature of the water leaving the unit, causing it to stop working to stay safe.
Your boiler has detected a faulty reading from the sensor that monitors the temperature of the water returning to the unit, causing it to shut down to prevent damage.
Your boiler has detected a faulty sensor reading in the pipework that carries water back from your radiators, preventing it from heating your home correctly.
Your boiler has detected a faulty sensor that is incorrectly measuring the temperature of the water moving through your heating system, causing it to shut down to prevent damage.
Your boiler's electronic control system is unable to correctly read temperature data from one of its internal sensors, causing it to stop operating to ensure safety.
Your boiler has stopped working because it cannot correctly measure the temperature of the water flowing through it, causing the system to shut down for safety.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water inside it, causing the system to shut down for safety.
Your boiler has detected an issue with one of its internal safety sensors, which is preventing it from firing up to keep your home warm.
Your boiler has failed to ignite and has shut itself down as a safety precaution because it cannot start the heating process.
Your boiler has attempted to start but failed to stay lit, so it has shut itself down as a safety precaution.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler is unable to read the temperature of the water being sent to your radiators, so it has shut down as a precaution to prevent overheating.
Your boiler is struggling to accurately detect the temperature of the water it is heating, so it has turned itself off to prevent the system from overheating.
Your boiler has detected that a flame is still burning inside even though it has commanded the system to turn off, which means it has safely shut itself down to prevent a hazard.
Your boiler's control panel is unable to communicate with the main internal computer, causing the system to stop functioning correctly.
Your boiler has lost its connection to a temperature sensor, meaning it no longer knows how hot it is and has stopped working as a safety precaution.
Your boiler has detected that the water is heating up or cooling down much faster than it should, which typically indicates a restricted flow inside the system.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes