58 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Tap any card for details
Your boiler has detected an internal issue with its electronic control system that prevents it from starting up safely.
Your boiler is displaying a status message meant for solar panel systems, which likely means the control system has a minor software configuration error.
Your boiler is struggling to communicate with your solar water heating system, which may be affecting how your water is warmed by the sun.
Your boiler's computer software is reporting a version mismatch or a communication error between its internal electronic systems.
Your boiler’s internal computer is reporting an issue with its own software settings, which is currently preventing the system from operating correctly.
Your boiler is having trouble 'reading' its internal settings because a small plug that tells the computer how to operate the system has become loose or faulty.
Your boiler has lost communication with its internal configuration chip, meaning it does not know how to operate correctly.
Your boiler's computer is having trouble communicating internally, which is preventing it from starting up correctly.
Your boiler's computer system has detected a mismatch or communication error in its internal software configuration.
Your boiler is operating exactly as it should and is currently warming your home.
Your boiler is currently heating your hot water and is working exactly as it should be.
Your boiler is perfectly fine and is simply taking a short break between heating cycles to prevent unnecessary wear.
Your boiler is currently idle and functioning perfectly, simply waiting for a request from your thermostat or hot water tap to start heating.
Your boiler has temporarily stopped because it detected that the water inside is significantly hotter than the temperature you have set it to reach.
Your boiler has been accidentally switched into a specific testing mode used by engineers to check emissions, which temporarily overrides normal heating and hot water operation.
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 is temporarily pausing to prevent the water from overheating, which is a normal protective feature and not a sign of a breakdown.
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's computer chip is not communicating correctly with the main control board, which is preventing the system from starting up safely.
Your boiler is struggling to accurately read the temperature of the water circulating through your heating system, which may prevent it from heating your home correctly.
Your boiler has lost the digital connection between its main parts, meaning it cannot process instructions to heat your home or water.
Your boiler has stopped working because the water pressure inside the heating system has dropped below the required level.
Your boiler is simply reminding you that it is time for its regular annual service to ensure it continues to operate safely and efficiently.
Your boiler is struggling to accurately measure the temperature of the water it is heating, so it has safely shut down to prevent overheating.
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 temporarily unable to detect the temperature outside, so it will continue to provide heating and hot water by assuming a standard outdoor temperature.
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 because it has lost the signal from the sensor that measures how cold it is outside, meaning it cannot automatically adjust your heating based on the weather.
Your boiler has lost the ability to accurately measure the temperature of the water flowing through the system due to a faulty electrical connection.
Your boiler has lost its connection to the component that monitors how hot the water inside the system is, so it has stopped working as a safety measure.
Your boiler has detected a faulty electrical signal from its internal temperature monitoring system, causing it to shut down for safety to prevent overheating.
Your boiler has lost communication with a key temperature sensor, causing it to shut down for safety because it cannot correctly monitor heat levels.
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 detected an internal communication error with the mechanism that controls the gas supply, meaning it is unable to start safely.
Your boiler is struggling to detect the correct flow of gas needed to fire up and heat your home safely.
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.
BoilerFaultCodes