31 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler's internal computer brain is unable to talk to the front display panel, meaning the system cannot receive instructions to provide heating or hot water.
Your boiler has lost its connection to the sensor that measures the water temperature as it leaves the unit, meaning it cannot safely judge how much heat to provide.
Your boiler has stopped working because it cannot communicate with the sensor that monitors the temperature of the water returning to the unit.
Your boiler has stopped working because it thinks the main water temperature sensor is broken or there is a problem with its internal wiring.
Your boiler has stopped working because it cannot correctly read the temperature of the water returning to the unit due to an electrical connection issue.
Your boiler has detected an electrical fault with the internal sensor that monitors the temperature of its hot water storage tank.
Your boiler has shut down because it has detected an unsafe increase in internal temperature, likely caused by a sensor fault or an issue with water flow.
Your boiler has stopped working because the water pressure is too low for it to operate safely.
Your boiler has detected that water isn't moving through the system fast enough, causing a large temperature difference that has triggered a safety shutdown.
Your boiler is overheating too quickly because water isn't flowing through the system correctly, often due to low pressure or trapped air.
Your boiler has detected an internal electrical connection issue that is preventing it from running safely.
Your boiler has detected a flame when there shouldn't be one, which has caused the system to shut down for safety.
Your boiler is failing to light the gas flame, meaning it cannot provide heat or hot water.
Your boiler has lost its flame while running and cannot manage to restart itself, likely due to a temporary interruption in the gas supply or a component failure.
Your boiler has detected a problem with the fan that safely pushes waste gases out of your home, causing the system to shut down for safety.
There is a communication error between your boiler and its controls, often caused by an electrical wiring fault or a heavy load on the internal data connection.
Your boiler has detected a technical communication error between the main control board and the gas valve, preventing it from lighting safely.
Your boiler has detected a potential internal gas leak or an electrical failure that stops the gas supply from closing correctly, so it has shut down for safety.
Your boiler's internal computer brain has developed a memory error and can no longer process instructions correctly.
Your boiler has detected an electrical fault within its internal sensors or control board, which has caused the system to shut down for safety.
Your boiler’s internal computer brain is overheating, which has caused the system to shut down for safety.
Your boiler's main control board is receiving an incorrect electrical signal from the flame sensor, meaning the system cannot safely confirm if the burner is lit.
Your boiler’s internal computer boards are having trouble communicating because they haven't been properly synced or configured to recognize each other.
Your boiler has detected that a temperature sensor is sending a stuck or frozen reading, preventing it from heating your home or water safely.
Your boiler has detected that its temperature sensors are giving conflicting or incorrect readings, causing it to shut down for safety.
Your boiler's internal sensor that monitors water pressure has lost electrical contact or has failed, causing the system to stop working for safety.
Your boiler has detected an electrical issue with its internal water pressure sensor, meaning it cannot accurately tell if there is enough water in the system to run safely.
Your boiler has stopped working because it cannot detect the necessary change in pressure when the pump starts up.
Your boiler has detected a safety-related electrical fault within its internal wiring or a heat protection fuse, causing it to shut down to prevent damage.
Your boiler is struggling to remove excess water or is experiencing a communication error with an external safety part, causing it to shut down to prevent damage.
Your boiler is taking a mandatory cooling break to prevent overheating after a period of intense work.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes