23 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler's internal computer is experiencing a communication error, meaning it cannot correctly process signals from its internal sensors and has safely shut down to prevent incorrect operation.
Your boiler has detected an electrical fault with the internal sensor that monitors water temperature, meaning it cannot safely regulate heat and has shut down.
Your boiler is receiving too little electricity from the mains supply to operate safely and has shut down as a precaution.
Your boiler has likely overheated or a sensor has detected an electrical fault, causing the system to shut down for safety.
Your boiler is unable to create the spark needed to light the gas and start the heating process.
Your boiler has stopped working because it cannot detect the flame needed to heat your water and radiators safely.
Your boiler has stopped working because the fan that removes waste gases is not spinning at the correct speed.
Your boiler has shut down because it thinks the water inside is getting too hot, which is usually caused by a blockage or a pump issue preventing water from circulating properly.
Your boiler has detected an internal electrical fault where a component controlling the gas supply has stuck in the 'on' position, preventing the system from operating safely.
Your boiler's internal pump has stopped circulating water, which prevents your heating and hot water from working to protect the system from overheating.
Your boiler has lost connection with the sensor that monitors the weather outside, which may cause your heating to run at the wrong temperature.
Your boiler has lost its connection to the outside temperature sensor, which helps it decide how hard it needs to work based on the weather.
Your boiler has lost connection with its outdoor thermometer, meaning it cannot automatically judge how hard it needs to work based on the weather outside.
Your boiler is having trouble communicating with your thermostat or indoor temperature sensor due to a wiring fault, which may prevent your heating from turning on correctly.
Your boiler has lost its connection to the sensor that measures the outdoor temperature, meaning it cannot automatically adjust its performance based on the weather.
Your boiler has lost connection with its indoor thermostat, meaning it cannot correctly measure the temperature inside your home to control the heating.
Your boiler has detected a fault with the sensor that monitors hot water temperature, meaning you will likely experience cold or lukewarm water from your taps.
Your boiler has lost the connection to the sensor that measures the temperature of your hot water, so it cannot accurately heat your taps or shower.
Your boiler has lost its connection to your smart thermostat or external heating controller.
Your boiler has detected a fault with the internal thermometer that monitors exhaust gases, causing the system to shut down for safety.
Your boiler has detected a signal failure from a safety sensor that monitors the temperature of exhaust gases, causing the system to shut down for protection.
Your boiler has shut down because it detected that the exhaust gases are getting too hot, which is a safety feature to prevent damage to the system.
Your boiler has detected a faulty sensor that monitors the temperature of the gases leaving your system, which prevents the boiler from operating safely.
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BoilerFaultCodes