28 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected that it has become too hot and has automatically shut itself down to prevent internal damage.
Your boiler is trying to start but failing to stay lit, which means it cannot produce any heating or hot water for your home.
Your boiler has detected an internal error where it thinks a flame is present when it actually isn't, which is a safety lockout preventing the unit from operating.
Your boiler has detected that the flame is not turning off correctly when it should, which is a safety concern that requires an expert to inspect.
Your boiler is struggling to accurately measure the temperature of your stored hot water, so it has safely stopped heating the tank to prevent overheating.
Your boiler is unable to read the water pressure level because the sensor responsible for checking it is faulty or has a loose connection.
Your boiler is struggling to confirm that the burner has safely lit, causing it to shut down to prevent the release of unburnt gas.
Your boiler has stopped because the flame inside went out while it was trying to heat your water or home.
Your boiler's internal computer chip is not being recognised correctly, which is preventing it from starting up safely.
Your boiler's computer is struggling to identify the specific configuration chip meant for your model, causing it to shut down for safety.
Your boiler is failing to stay safely lit because it cannot reliably detect the flame needed to heat your water.
Your boiler has failed to stay lit because it cannot maintain a stable flame at the lowest power setting.
Your boiler is trying to start up but it cannot detect a flame, so it has safely shut itself down to prevent gas from building up.
Your boiler is trying to ignite but cannot detect a flame, meaning it is currently unable to provide heating or hot water for safety reasons.
Your boiler has detected an unreliable temperature reading from its internal sensors and has shut down as a precaution to prevent damage.
Your boiler has detected that the temperature reading from its internal pipes is incorrect, so it has safely shut down to prevent potential overheating.
Your boiler is struggling to pump water around your heating system efficiently, likely due to a blockage in the unit or a problem with the internal pump.
Your boiler is struggling to circulate water properly, which means it cannot safely heat your home or water.
Your boiler has detected that the water temperature inside the system has become dangerously hot and has shut itself down to prevent damage or overheating.
Your boiler is overheating because water isn't circulating through your radiators properly, likely due to low pressure or an issue with the internal pump.
Your boiler is struggling to move water around effectively, causing it to overheat very quickly because the heat isn't being transferred into your radiators or water properly.
Your boiler is shutting down because it cannot circulate water through your heating system, likely due to low pressure or a blockage.
Your boiler has detected that water is heating up or cooling down at two different spots in a way that suggests a circulation problem or a faulty reading, so it has stopped working to prevent potential damage.
Your boiler has detected that water isn't moving through the unit as expected, likely due to a circulation issue or a sensor that is no longer properly attached.
Your boiler has detected a fast leak in your radiator system, meaning it has lost water pressure too quickly for it to operate safely.
Your boiler has detected that the water pressure in your heating system is falling away much faster than it should, causing it to shut down to protect itself.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Your boiler has stopped working because the water pressure inside your heating system has dropped below the required level.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes