23 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is struggling to vent exhaust gases properly when it starts up, which could lead to fumes building up in your home.
Your boiler is allowing exhaust fumes to escape into your home, which is a serious safety concern that must be addressed immediately.
Your boiler has stopped working because of a communication failure between its internal electronic brains and a fault in the ignition system.
Your boiler's main internal computer has encountered a processing error and cannot safely operate.
Your boiler has sensed a blockage or a pump failure that is stopping water from moving through the system properly.
Your boiler has detected that the water pressure in the central heating system is too low to operate safely.
Your boiler has stopped working because it has lost the electrical connection to its temperature sensor.
Your boiler has detected that the electrical wiring coming into the unit is connected the wrong way round.
Your boiler's main control board has lost contact with the digital display or internal computer, meaning it can no longer send or receive instructions.
Your boiler has stopped working to protect itself and needs to be restarted, though it may take a few attempts to get it running again.
Your boiler has stopped working because the flame inside failed to light or stay on.
Your boiler has detected that a temperature sensor cable has disconnected or become faulty, preventing the system from monitoring water flow correctly.
Your boiler has lost connection with its outside temperature sensor, which means the heating might not adjust correctly to the weather.
Your boiler has stopped working because it cannot correctly measure the temperature of the water returning to the unit.
Your boiler has detected a problem with a sensor that monitors the temperature of the exhaust gases, and it has likely stopped working as a safety precaution.
Your boiler has stopped working because an internal sensor that monitors the temperature of the heating coil is no longer sending a correct reading.
Your boiler has stopped working because one of its internal sensors is failing to monitor the temperature of the water returning to the unit.
Your boiler's internal thermometer that measures the air around it has stopped working properly, preventing the system from operating safely.
Your boiler has shut itself down because the internal gases have reached an unsafely high temperature to protect the system from damage.
Your boiler has detected very cold temperatures and is automatically running to prevent the internal pipes from freezing.
Your boiler has detected an electrical fault with its internal temperature sensors and has stopped running as a safety precaution.
Your boiler's temperature sensor has stopped sending the correct signals, meaning the system doesn't know how hot the water is and has shut down as a precaution.
The boiler's internal computer has encountered a communication error between its memory and control systems, which prevents it from running correctly.
BoilerFaultCodes