84 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler's internal computer is unable to talk to its display panel, meaning the system has stopped working to protect itself.
Your boiler's internal computer is having trouble talking to its main control board, which is preventing it from starting up correctly.
Your boiler is currently just displaying a setting that controls how long it waits before turning the burner on again, rather than indicating a fault.
Your boiler has stopped working because it has lost the connection to the sensor that monitors the temperature of the water flowing through your heating system.
Your boiler has lost the signal from the sensor that monitors the temperature of the water returning to the unit, causing it to shut down for safety.
Your boiler has stopped working because a sensor that measures the water temperature is providing an incorrect electrical signal that the system cannot understand.
Your boiler has identified a faulty electrical signal from the pipe that carries water back from your radiators, preventing it from heating your home reliably.
Your boiler has lost the ability to accurately measure the temperature of the water used for your taps, which means it has stopped heating your hot water to prevent potential overheating.
Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Your boiler has shut down because the water inside is not circulating properly, causing a significant temperature difference between the water leaving the boiler and the water returning to it.
Your boiler has switched itself off because the water inside is heating up much faster than it can circulate away, which often signals a blockage or a pump issue.
Your boiler has detected that the exhaust gases are getting dangerously hot and has shut itself down to prevent damage to the internal components.
Your boiler is unable to control the flow of gas necessary to ignite the flame, so it has shut down as a safety precaution.
Your boiler has detected a signal suggesting a flame is present when it should be off, so it has shut itself down as a safety precaution to prevent a potential gas buildup.
Your boiler is trying to ignite but cannot get the flame to stay lit, so it has safely shut itself down to prevent gas from escaping.
Your boiler is trying to stay lit but keeps failing, which means it has stopped providing heating and hot water for safety reasons.
Your boiler's internal extraction fan is struggling to spin, which prevents it from safely venting exhaust gases and means your heating and hot water will not work.
Your boiler's internal communication system is not receiving the correct electrical signal, which is preventing it from operating correctly.
Your boiler has detected an issue with the internal electrical connection that controls the flow of gas, meaning it cannot safely start up.
Your boiler has detected an issue with its internal gas valve and has shut down to ensure your safety.
Your boiler's computer memory has experienced an internal error, which prevents it from operating safely and reliably.
Your boiler has detected an issue with its internal computer or a wiring connection, causing it to shut down for safety.
Your boiler's main computer board is detecting that its internal components are getting too hot, so it has shut down to protect itself from potential damage.
Your boiler has detected an internal error with its computer chip or the sensor responsible for checking that the flame is lit, meaning it has shut down for safety reasons.
Your boiler is struggling to keep the internal flame burning steadily, so it has safely shut down to prevent any issues.
Your boiler's internal computer has lost its identification settings, preventing it from knowing exactly which heating unit it is.
Your boiler is confused because it is getting conflicting or stuck temperature readings, so it has stopped working to prevent potential overheating.
Your boiler is struggling because it detects a confusing difference in water temperatures between the two main internal pipes, preventing it from heating your home safely.
Your boiler is struggling to detect the water pressure inside the system because the sensor is sending an incorrect signal, which prevents the boiler from firing up safely.
Your boiler's internal computer is receiving a confusing signal about the water pressure, causing it to shut down for safety.
Your boiler is struggling to detect a rise in pressure when it turns on, which usually means it cannot confirm that water is successfully circulating through your heating system.
Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent damage or fire risk.
Your boiler is struggling to safely dispose of exhaust gases or water waste, so it has safely shut down to prevent any damage.
Your boiler has lost communication with the device that monitors your hot water temperature, causing it to stop producing hot water.
Your boiler is not detecting enough water inside the heating system to operate safely, possibly due to trapped air or a circulation problem.
Your boiler has detected that the water temperature readings at the start and end of its heating circuit do not match up properly, causing it to shut down to prevent damage.
Your boiler has detected that a temperature probe is not fitted correctly or has become loose, preventing it from accurately reading the water temperature.
Your boiler is currently running a self-diagnostic sequence to automatically remove trapped air from the system.
Your boiler is currently running a software test to check it is performing correctly at its highest power setting.
Your boiler is currently running a routine internal test to ensure it is burning fuel efficiently, rather than indicating a fault.
Your boiler is currently in a manual maintenance mode used for filling or draining the system, rather than operating normally.
Your boiler is currently in standby mode because it has not been asked to provide any heating or hot water.
Your boiler is currently initiating its start-up sequence and is preparing to light the burner to provide heating.
Your boiler is simply preparing its internal pump to circulate water before it begins heating your home, meaning it is operating normally.
Your boiler is currently trying to light the flame to start your heating, but it is taking a few moments longer than usual to ignite.
Your boiler is currently operating normally and is actively heating your radiators.
Your boiler is currently just finishing its cooling-down cycle after being used, which is a normal part of its operation.
Your boiler is currently cooling down its internal components after the heating has been running, which is a normal part of the shutdown process.
Your boiler is simply moving leftover warm water around your heating pipes to distribute the remaining heat, which is a normal part of its cooling-down process.
Your boiler is perfectly fine; it is currently taking a short, programmed rest to prevent it from switching on and off too frequently.
Your boiler is simply letting you know that it is currently busy heating water for your taps or shower.
Your boiler is currently initiating the sequence to prepare hot water for your taps and shower.
Your boiler is currently trying to light the flames needed to heat your hot water but is struggling to get them started.
Your boiler is currently operating normally and is actively heating your hot water.
Your boiler is currently cooling itself down after being used for hot water, which is a normal part of its operation.
Your boiler is simply finishing its cooling process after you recently used the hot water tap, which is a normal part of its operation.
Your boiler is simply finishing a cycle by circulating water to cool itself down, and this is a normal part of the standard shut-down process.
Your boiler is simply letting you know that it is currently preparing to provide hot water to your taps or shower.
Your boiler is currently just in the process of starting up its internal air fan to prepare for heating your hot water.
Your boiler is simply preparing to deliver hot water by briefly running the internal water pump before lighting the burner.
Your boiler is currently trying to light up to heat your hot water, but hasn't yet successfully started the process.
Your boiler is currently working correctly and is heating up water for your taps or shower.
Your boiler is currently cooling itself down after being used to heat your hot water and is not experiencing a fault.
Your boiler is simply finishing a cooling process after you last used your hot water tap.
Your boiler is simply finishing its cooling process after you last used the hot tap, and this is a normal part of its operation.
Your boiler is taking a short, scheduled break to prevent the system from getting too hot and wearing out the parts prematurely.
Your boiler is currently waiting for a signal from your room thermostat or smart controller, which is preventing the heating from turning on.
Your boiler is currently idle because it is set to summer mode or your thermostat is not asking for any heating.
Your boiler is temporarily pausing because it detected that the internal fan responsible for moving air is not spinning at the exact speed it expects.
Your boiler has detected that the external temperature is very low and has automatically switched on its internal heater to prevent the pipes from freezing.
Your boiler has detected that the air-intake system has stopped working correctly and is pausing itself to prevent unsafe operation.
Your boiler has temporarily stopped firing because a safety switch—often linked to how it drains water or monitors temperature—has triggered a protective shutdown.
Your boiler has detected that the water pressure inside the system is getting too high, which may cause a safety relief valve to drip or open.
Your boiler has detected a blockage or communication error in its venting system, which is preventing it from safely starting up.
Your boiler is struggling to stay lit at its lowest power setting and has entered a temporary safety pause to prevent damage.
Your boiler is temporarily pausing its operation to protect itself because the water is not moving through the system quickly enough.
Your boiler has temporarily paused to protect itself because the water pressure inside the system is currently too low to run safely.
Your boiler is temporarily paused for a few minutes as a built-in safety measure to prevent it from overheating.
Your boiler has temporarily restricted its performance because it is struggling to intake air correctly, likely due to strong winds or an obstruction in the flue.
Your boiler has stopped working because the water pressure inside the heating system has dropped below the required level.
Your boiler is currently running a routine self-check of its internal temperature sensors, so it has temporarily paused heating to ensure everything is working correctly.
Your boiler is currently performing a routine automated safety check of its internal sensors and will resume normal operation once the process is complete.
Your boiler is currently performing a brief automatic self-check and will resume normal operation as soon as the test is complete.
BoilerFaultCodes