40 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected that the central heating system is running too hot and has automatically shut down to prevent damage.
Your boiler is able to heat your hot water, but it is struggling to produce enough heat for your radiators because it cannot switch to full power.
Your boiler is confused about its heating levels, causing it to run continuously at the wrong temperature while failing to warm up your hot water cylinder properly.
Your boiler is struggling to keep up because either too much hot water is being used at once or the flow through the system is restricted.
Your boiler has shut down because a sensor has detected that the water inside is getting too hot.
A diagnostic switch inside your boiler's control panel has been accidentally left turned on, and simply needs to be switched back off.
Your boiler is temporarily shutting down because too many of your radiators are turned off or blocked, restricting the flow of water.
Your boiler has safely shut down because a built-in safety sensor has detected a potential issue and cannot verify safe operating temperatures.
Your boiler is temporarily locked out because a temperature sensor is giving incorrect readings or needs to be cleaned.
Your boiler has stopped working because the internal water pump is either stuck, disconnected, or completely broken, which prevents water from circulating.
Your boiler has temporarily stopped working because the water pressure inside the heating system has dropped too low.
Your boiler has detected an incorrect power setting configuration or an issue with the internal speed control.
Your boiler is struggling to breathe properly because there is a blockage or too much debris in the air intake or exhaust system.
Your boiler has stopped working because the fan that helps remove waste gases is not spinning or communicating correctly with the system.
Your boiler has stopped working because it cannot properly measure the temperature of the water coming back into the system.
Your boiler has shut down because a safety sensor has detected that the burner area is getting too hot or is failing to register a secure connection.
Your boiler has stopped working because an internal electrical fuse has blown, most likely due to an issue with the valve that controls your gas supply.
Your boiler has stopped working because its internal sensors or control system have detected a technical communication error.
Your boiler has lost communication with one of its internal sensors, meaning it cannot accurately monitor temperatures to run safely.
Your boiler is unable to create a spark to light the gas, meaning your heating and hot water will not work.
Your boiler has shut down because the mixture of gas and air required for a safe flame is incorrect, often due to a blockage or a dirty internal component.
Your boiler is unable to light the flame because the gas supply is blocked or a safety sensor is cutting out.
Your boiler is not receiving a steady supply of gas or has air trapped in the pipes, preventng the flame from lighting properly.
Your boiler has failed to detect a flame, which means it cannot stay on safely and has stopped working for your protection.
Your boiler has detected an issue with the electricity supply while trying to run.
Your boiler has experienced an internal electrical short circuit which has likely blown a protective fuse, causing it to stop working entirely.
Your boiler has experienced a temporary software or ignition glitch and simply needs to be rebooted to clear the error.
Your boiler has stopped working because the supply of gas reaching it is too low to operate safely.
Your boiler has detected that gas is potentially still flowing or a flame signal is present when it should be turned off, which is a safety concern.
Your boiler's internal control module is failing to communicate with the fan, causing the system to shut down immediately after trying to start.
Your boiler has detected a problem with how it monitors gas supply pressure, meaning it cannot safely confirm there is enough fuel to stay lit.
Your boiler's internal communication chip is either faulty or has come loose, causing the system to stop working.
Your boiler has stopped working because it has lost a secure electrical connection to the valve that controls the gas supply.
Your boiler has lost communication with your wall thermostat, meaning it cannot receive the signal to turn on your heating.
Your boiler has lost its electrical power supply or there is a fault with the incoming electricity to the unit.
Your boiler’s internal control system has encountered a critical electronic failure that it cannot clear itself.
Your boiler is producing more heat than your hot water tank can safely handle, causing the system to stop for protection.
Your boiler is struggling to control how much water flows through the system, which can prevent it from heating up correctly.
Your boiler has detected a break in an internal electrical connection or a safety thermostat issue, causing it to safely shut down.
Your boiler's main internal computer has developed a fault and can no longer control the heating system correctly.
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BoilerFaultCodes