68 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected an internal system error and safely shut down to prevent further issues.
Your boiler has stopped working because it has detected an unspecified internal safety fault.
Your boiler is struggling to control its internal gas supply, which means it has safely shut itself down to prevent any risk of incomplete combustion.
Your boiler is struggling to control the gas supply it needs to stay lit, so it has shut down to keep your home safe.
Your boiler is struggling to manage the gas supply required to light the flame and heat your water, which has caused it to shut down for safety.
Your boiler has lost communication with an optional safety monitoring device, which is preventing it from operating correctly.
Your boiler has lost communication with an optional safety device, meaning it has shut down as a precaution to prevent unsafe operation.
Your boiler is having a communication error with an optional safety monitoring device, which is causing the system to stop functioning as a precaution.
Your boiler has registered a general internal safety fault and has stopped working to prevent any potential damage.
Your boiler has detected that the water inside the heating system has become too hot and has automatically shut 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 is struggling to circulate water properly or is overheating because it cannot detect the expected changes in water temperature.
Your boiler has stopped because it cannot maintain a stable flame to heat your water.
Your boiler has detected an unspecified internal problem and has safely stopped working to prevent further issues.
Your boiler is failing to light because it cannot detect a flame, which may be caused by a temporary gas supply issue.
Your boiler is trying to start but cannot detect a flame, likely because the gas supply is blocked or the ignition system is failing to spark.
Your boiler is failing to light because it is not receiving enough gas or is having trouble sparking, meaning you currently have no heating or hot water.
Your boiler has detected an issue with the system that controls the flow of gas, meaning it has shut itself down to keep your home safe.
Your boiler is having trouble controlling the flow of gas needed to stay lit, so it has shut down as a safety precaution.
Your boiler has detected a general internal system error and has temporarily stopped working to keep your home safe.
Your boiler has detected an issue with an optional safety accessory linked to the system.
Your boiler has temporarily stopped working because it has detected a loose or faulty connection to the internal fan that safely removes combustion gases.
Your boiler is temporarily unable to accurately read its own water temperature, so it has safely shut down to prevent overheating.
Your boiler has detected an issue with the gas supply to the burner, meaning it cannot safely light or stay ignited.
Your boiler has temporarily stopped working because it cannot detect a proper supply of gas.
Your boiler has stopped working because it is not receiving a proper supply of gas.
Your boiler has lost the ability to accurately measure the temperature of the water flowing through the central heating, so it has safely shut down to prevent overheating.
Your boiler has lost the ability to accurately measure the temperature of your hot water, which temporarily disables the hot water supply.
Your boiler has temporarily stopped working because the water pressure inside the system has dropped too low.
Your boiler has detected that water is not flowing properly through its internal system, so it has safely shut down to prevent overheating.
Your boiler has temporarily stopped working because it cannot move water around the system properly.
Your boiler is temporarily unable to accurately measure the temperature of the water flowing through the system due to a faulty sensor.
Your boiler has stopped working because it has lost its gas supply or the flame has unexpectedly gone out.
Your boiler has temporarily stopped working because it has detected an interruption in its gas supply.
Your boiler has temporarily stopped working because it cannot accurately read the temperature of the water flowing through it.
Your boiler has detected an issue with the internal fan that safely clears combustion gases, so it has locked out to keep your home safe.
Your boiler has detected a fault with the internal sensor that monitors the temperature of your central heating water, causing the system to stop working as a safety precaution.
Your boiler has stopped working because it has detected a blockage or issue with the pipe that carries exhaust gases safely outside your home.
Your boiler is struggling to accurately measure the temperature of your hot water because a sensor is not working properly.
Your boiler is failing to measure the temperature of your hot water properly, which usually stops it from working correctly.
Your boiler has stopped working because it is having trouble burning gas properly to create heat.
Your boiler has temporarily stopped working because the water pressure inside the heating system has dropped too low.
Your boiler has switched itself off because it has reached an unsafe temperature, usually due to a lack of water flow or a circulation problem.
Your boiler has temporarily stopped working because the water pressure inside the system has dropped too low.
Your boiler has stopped working because the water pressure in the system has dropped too low and needs topping up.
Your boiler is struggling to move hot water around the system, which is usually caused by a blockage or a pump issue that is preventing the unit from cooling itself down.
Your boiler has detected that water is not flowing properly through the internal heating system.
Your boiler has lost its flame while running, which means it has safely shut down to prevent issues.
Your boiler has shut down because a sensor has detected that the exhaust gases are becoming too hot, which is a safety feature to prevent damage.
Your boiler has failed to light because it is not receiving enough gas or cannot detect the flame used to heat your water.
Your boiler has stopped working because the internal fan, which safely exhausts gases, is not spinning at the correct speed or has lost power.
Your boiler has detected that water is not flowing properly through the system, so it has temporarily stopped working to protect itself.
Your boiler has automatically shut down because an internal safety switch detected that the water inside reached too high a temperature.
Your boiler has tried to start up but the gas flame has gone out or failed to light properly.
Your boiler has stopped working because it cannot detect the airflow needed to safely burn gas.
Your boiler has lost track of how hot the water inside the heating system is because a temperature sensor is faulty.
Your boiler has detected a problem with the sensor that monitors the temperature of your hot water, meaning your taps may not get as hot as they should or stay consistent.
Your boiler has detected a problem with the temperature sensor on the central heating system, so it has safely shut down to prevent overheating.
Your boiler thinks a flame is present even when it should be off, causing it to shut down for safety.
Your boiler has stopped working because it has detected an issue coming from an external device or smart control connected to it.
Your boiler is failing to light the burner because it cannot detect or produce a reliable ignition spark.
Your boiler has stopped working because it cannot properly detect the flame or regulate its gas supply.
Your boiler has automatically shut down because it detected dangerously high temperatures inside the unit.
Your boiler has temporarily stopped working because the water pressure inside the heating system has dropped too low.
Your boiler has detected trapped air or a temperature reading issue in the water system, which usually causes it to pause for safety.
Your boiler has detected an issue with the internal valve that switches between heating your home and providing hot water, meaning you may lose your heating or hot water supply.
Your boiler is not detecting the flow of tap water correctly, meaning you likely have no hot water coming through the taps.
Your boiler has detected an issue with measuring its internal temperature or water flow, causing it to shut down for safety.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes