50 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler's internal memory chip hasn't activated correctly, meaning the central control unit doesn't recognize which model it is supposed to be operating.
Your boiler's computer memory card has failed or is unreadable, meaning the system cannot talk to its internal controls to operate.
Your boiler thinks a flame is present even when it should be turned off, which prevents it from starting up safely.
Your boiler is not firing up to provide heat or hot water because it is having trouble starting the flame.
Your boiler detects a flame when there shouldn't be one, which usually indicates an electrical fault or a sensor issue.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Your boiler has lost power or was switched off while it was already trying to report a different fault, causing it to display this general error message.
Your boiler's fan has stopped working correctly, which means the system cannot safely clear waste gases and will not allow the boiler to start.
Your boiler has shut down because the exhaust gases are getting too hot, which suggests an internal component or the heat exchanger may be failing.
Your boiler is having trouble managing its internal electrical signal for the burner flame, meaning it cannot safely stay lit.
Your boiler has detected an internal communication problem between its electronic brain and the gas supply system, preventing it from firing up.
Your boiler’s internal computer has encountered a critical electronic failure and can no longer control the heating system safely.
Your boiler has stopped working because its internal sensors are reporting conflicting temperature readings that don't match up during a self-test.
Your boiler's electronic brain has encountered an internal software or hardware error, preventing the system from running safely.
Your boiler has detected that the water inside is getting too hot too quickly because it is not moving through the system properly.
Your boiler has likely stopped working because the water returning to the unit is too hot, which happens when water isn't flowing through your radiators properly.
Your boiler is having trouble detecting the correct amount of water in the system, which is preventing it from heating your home safely.
Your boiler has shut down because it keeps losing water pressure and needs a manual top-up or a leak fixed.
Your boiler's internal computer has encountered a critical electronic failure that is preventing the system from starting safely.
Your boiler is struggling to keep its flame alight because it cannot breathe properly or get enough fuel.
Your boiler has detected an electrical fault with the internal sensor that monitors water temperature, causing the system to stop running for safety.
Your boiler has stopped working because it cannot communicate with the sensor that monitors the temperature of the water leaving the unit.
Your boiler has detected an electrical problem with the sensor that monitors hot water temperature, meaning it cannot safely heat your water.
Your boiler has detected a fault with the sensor that manages your hot water, likely meaning you won't have any hot water until it is fixed.
Your boiler has stopped working because the electrical power coming into it is too low to operate the system safely.
Your boiler has detected an issue with the electrical power timing coming into the house, meaning it cannot operate safely.
Your boiler has stopped working because a sensor that monitors the temperature of the water leaving the unit has failed or become disconnected.
Your boiler has stopped working because the water pressure inside the system has dropped too low.
Your boiler's control panel has developed a technical fault with the reset button, meaning it cannot be operated or cleared correctly.
Your boiler has detected that there is too much water in the system, which puts unnecessary stress on the pipes and internal components.
Your boiler's internal computer brain is having trouble communicating with the display panel on the front, preventing the system from operating correctly.
Your boiler has detected an electrical fault with the internal sensor that monitors the temperature of the water returning to the unit, causing it to stop running for safety.
Your boiler has lost communication with the sensor that monitors water returning from your radiators, causing it to stop running as a safety precaution.
Your boiler has detected an electrical fault with the sensor that monitors exhaust gases, causing the system to shut down for safety.
Your boiler's main control board is unable to talk to the display panel on the front, meaning the system cannot carry out your instructions.
Your boiler has detected an electrical fault with the sensor that monitors exhaust gases, causing the system to shut down for safety.
Your boiler has encountered a critical system error that has forced it to shut down to prevent damage.
Your boiler is unable to start because its internal memory chip is missing or not properly connected to the main control board.
Your boiler has detected that the water pressure in the system is too low to run safely and has stopped working to protect itself.
Your boiler has lit correctly but the flame has been lost during operation, causing the system to shut down for safety.
Your boiler has detected a problem with its internal fan, which means it cannot safely blow waste gases out of the flue and has shut down as a precaution.
Your boiler has detected that water is not circulating correctly or a temperature sensor is giving an incorrect reading, causing the system to shut down for safety.
Your boiler has detected a problem with the sensor that monitors the temperature of the water returning from your radiators, causing the system to shut down for safety.
Your boiler has lost connection with the sensor that measures the temperature outside, which may cause your heating to run at the wrong temperature.
Your boiler has detected that the electricity supply coming from the grid is currently too weak for it to operate safely.
Your boiler's internal computer has encountered a critical error and can no longer control the heating system safely.
Your boiler has shut down because the internal water temperature has become too hot.
Your boiler is failing to keep its flame lit, which means the system has safely shut down to prevent issues.
Your boiler has stopped working because it has been reset too many times in a short period and has locked itself out for safety.
Your boiler thinks it sees a flame even though it hasn't started the ignition process, so it has shut down as a safety precaution.
BoilerFaultCodes