30 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has lost communication with the sensor that measures the temperature outside, which may cause your heating to behave unpredictably.
Your boiler has detected a problem with the sensor that monitors the temperature of the water leaving the unit, meaning it cannot safely regulate heat.
Your boiler has detected an issue with the sensor that monitors the temperature of the water returning from your radiators, preventing it from heating your home safely.
Your boiler has detected a problem with the sensor that manages your hot water, which means it cannot accurately tell if the water is at the right temperature.
Your boiler has lost the ability to communicate with its internal control systems or the external thermostat, meaning it cannot receive instructions to heat your home.
Your boiler has detected that the water pressure is either too low or too high, or the sensor that monitors this pressure has lost its connection.
Your boiler is busy removing air bubbles from the pipes after the water pressure was topped up, and it will return to normal operation in about seven minutes.
Your boiler has shut down because it has detected an internal temperature that is too high, often caused by a lack of water circulation.
Your boiler has shut down because there is too much water pressure in the system, which can put strain on the internal seals.
Your boiler has detected that the water pressure is too low to work properly, so it has automatically reduced its power to protect the system.
Your boiler has detected that a critical internal safety link or a water pressure switch connection is broken, preventing it from starting up.
Your boiler's fan is failing to start, which means the system cannot safely vent exhaust gases and has shut down as a precaution.
Your boiler has tried to start several times but cannot light a flame, meaning you will not have any heating or hot water until it is fixed.
Your boiler has stopped working because the fan that clears away waste gases is not spinning at the correct speed or has lost communication with the main control board.
Your boiler has stopped working because it cannot move water through the system properly, often due to a blockage or a pump issue.
This is a normal status message showing the boiler is returning to standard operation after a maintenance test, and it is not an actual fault.
Your boiler is simply finishing its internal setup process and is returning to normal operation, so there is no actual fault or problem.
Your boiler has detected an issue with the sensor that monitors the temperature of the water leaving the unit, which has caused it to stop running for safety.
Your boiler has detected an issue with the sensor that monitors water returning from your radiators, preventing it from heating your home safely.
Your boiler's internal computer brain has temporarily lost its ability to talk to the control sensors and requires a manual power restart.
Your boiler has detected that water is not circulating properly, which could mean the pump has stopped working or the water pressure is too low.
Your boiler is currently running an automatic cycle to clear trapped air from the system, which typically occurs after it has been powered on or refilled.
Your boiler has switched itself off because it has become too hot internally, often due to a lack of water flow or a blockage.
Your boiler has sensed that the water inside has become far too hot and has shut down as a safety precaution.
Your boiler has stopped working because the water pressure is critically low and needs to be topped up.
Your boiler has stopped working because the internal fan, which clears exhaust fumes, is unable to start up correctly.
Your boiler has tried to light several times but has failed to produce a flame, meaning your heating and hot water will not work.
Your boiler has stopped working because the fan that removes waste gases is not spinning at the correct speed.
Your boiler has detected that water is heating up too quickly or flowing in the wrong direction, often because something is blocking the circulation of water through the system.
Your boiler is displaying an advisory message indicating that specific chemical protection or anti-freeze has been added to the system water, rather than reporting an actual breakdown.
BoilerFaultCodes