50 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Heat 2
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Your boiler's internal memory chip is not communicating correctly with the main control board, meaning the unit cannot verify its own identity or settings.
Your boiler's internal memory card is either missing, corrupted, or not communicating correctly with the main control board.
Your boiler thinks it sees a flame even though it hasn't finished its start-up sequence, causing it to shut down for safety.
Your boiler has tried to light several times but cannot establish a flame, meaning your heating and hot water will not work.
Your boiler thinks a flame exists even when it shouldn't, which is a safety conflict that has caused the system to shut down.
Your boiler has become too hot and has shut down as a safety precaution to prevent damage.
Your boiler has lost power or was switched off while it was already trying to tell you about a different fault, and it now needs to be manually cleared.
Your boiler has stopped working because the internal fan, which safely pushes exhaust gases out of the flue, is not spinning correctly.
Your boiler has sensed that the exhaust gases are getting much hotter than they should be, and it has shut down to prevent damage to internal components.
Your boiler is having trouble detecting its own flame or has an internal electronic malfunction, preventing it from heating your home safely.
Your boiler has detected an internal electrical problem with the part that controls the gas flow, meaning it cannot ignite safely for heating or hot water.
Your boiler's internal computer has encountered a critical electronic failure and can no longer control the heating process 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 internal computer has encountered a critical electronic failure and can no longer safely control the heating process.
Your boiler has detected that the water inside is getting too hot because it isn't moving through the system properly.
Your boiler has stopped working because the water returning to the unit is too hot, typically meaning the heat isn't being moved away into your radiators effectively.
Your boiler is having trouble detecting or maintaining the correct water level, which has caused it to stop running for safety.
Your boiler has shut down because it keeps losing water pressure, which usually indicates a leak somewhere in your heating system or a faulty internal component.
Your boiler's computer brain has encountered an internal error and can no longer safely coordinate the heating process.
Your boiler has started an ignition sequence but the flame keeps going out, meaning the system cannot stay lit long enough to heat your home.
Your boiler has stopped working because it cannot correctly read the temperature of the water leaving the unit due to an electrical connection issue.
Your boiler has lost its connection to the sensor that monitors the temperature of the water leaving the unit, causing it to stop running for safety.
Your boiler has detected an electrical fault with the sensor that monitors your hot water temperature, meaning it cannot safely heat your water.
Your boiler has detected a fault with the sensor that manages your hot water, which usually means it cannot accurately tell if the water is at the right temperature.
Your boiler has detected that the electrical power coming from your mains supply is too low for it to operate safely.
Your boiler has detected an issue with the electrical power coming from the grid or a fault in its internal electronics, causing it to shut down for safety.
Your boiler has stopped working because it cannot accurately measure the temperature of the water leaving the unit due to a sensor communication failure.
Your boiler has detected that the water pressure is too low to operate safely and has shut down as a precaution.
Your boiler's control panel has developed a technical hardware fault and is no longer responding to the reset button.
Your boiler has detected that there is too much water in the system, which can cause excessive strain on the pipes and safety valves.
Your boiler's main control panel has lost connection with its internal brain, meaning the unit cannot receive instructions or fire up.
Your boiler has stopped working because it cannot correctly read the temperature of the water returning from your radiators.
Your boiler has lost communication with the sensor that monitors the temperature of the water returning to the unit, causing it to stop running for safety.
Your boiler has detected an electrical fault with the sensor that monitors exhaust gases, causing it to shut down for safety.
Your boiler's main control panel is having trouble talking to the internal computer, which means the boiler cannot receive commands to start up.
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's internal memory chip is missing or not properly connected, which means the main control board doesn't know how to operate the unit.
Your boiler has detected that the water pressure in the system is too low to run safely and has stopped working as a result.
Your boiler has lit correctly but the flame has gone out unexpectedly, often due to a problem with the gas supply or a blocked condensation pipe.
Your boiler has stopped working because the fan that safely clears exhaust gases is either not spinning or communicating correctly with the control system.
Your boiler has stopped working because it cannot properly measure the temperature of the water moving through the system.
Your boiler has detected a problem with the sensor that monitors the temperature of the water returning from your radiators, preventing it from heating your home efficiently.
Your boiler has lost communication with the sensor that measures the temperature outdoors, which may cause it to run less efficiently or fail to heat up properly.
Your boiler has detected that the electricity supply coming from the mains is too low for it to operate safely.
Your boiler's internal computer has developed an electronic error and is unable to control the heating system safely.
Your boiler has shut down because the water inside the system has become too hot, likely due to a circulation problem.
Your boiler has started an ignition process, but the flame has gone out unexpectedly, causing the system to shut down for safety.
Your boiler has been manually reset too many times in a short period and has locked itself out as a safety precaution.
Your boiler thinks it sees a flame even though it isn't supposed to be running, which is causing it to lock itself down for safety.
BoilerFaultCodes