47 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has stopped working because it can no longer accurately measure the temperature of the water leaving the unit.
Your boiler has failed to ignite and is not producing heat, which is usually due to an interrupted gas supply or a problem with the internal spark system.
Your boiler has stopped working because a sensor that monitors the temperature of the water returning to the unit has disconnected or failed.
Your boiler is failing to light the flame properly, which means it cannot heat your radiators or water.
Your boiler has got too hot and has automatically shut down for safety to prevent damage.
Your boiler has stopped working because a sensor that measures the temperature of the water leaving the unit has stopped sending a reliable signal.
Your boiler has stopped working because an internal temperature sensor has developed an electrical fault and is giving a false reading.
Your boiler has detected that water isn't moving through the internal pipes correctly, causing it to shut down to prevent overheating.
Your boiler has detected a internal blockage that is preventing water from flowing correctly and affecting the pressure.
Your boiler has stopped working because the water pressure is too low, and it has shut down to prevent damage.
Your boiler has detected that the electrical wiring is connected incorrectly or there is a problem with the mains power supply.
Your boiler has become too hot and has automatically shut down to prevent damage or danger.
Your boiler has stopped working because it cannot light the flame or keep it burning properly.
Your boiler has stopped working because the water pressure is too low for it to operate safely.
Your boiler has detected that water isn't moving through the system fast enough, causing a large temperature gap between the outgoing and incoming pipes.
Your boiler has stopped working because the water isn't circulating properly, likely due to a pump issue or trapped air in the system.
Your boiler has automatically shut down because the internal temperature of the exhaust gases has reached an unsafe level.
Your boiler thinks a flame is present even when the gas is turned off, which prevents it from starting up safely.
Your boiler has tried to start up several times but cannot establish a flame to begin heating your water.
Your boiler has lost its flame while running and is struggling to relight itself.
Your boiler has detected a problem with the way it receives gas or a communication failure within its internal control board.
Your boiler's main control board is struggling to identify which specific model it is due to an electrical communication error.
Your boiler is struggling to identify its specific model configuration due to an internal electrical communication error.
Your boiler has detected an electrical communication problem with the internal gas valve, which is preventing it from safely lighting the flame for heating and hot water.
Your boiler has detected a communication problem between the main computer and the gas valve, meaning it cannot safely light the flame to provide heating or hot water.
Your boiler has detected that the gas valve is not closing as quickly as it should, which has caused the system to shut down for safety.
Your boiler's internal computer brain has developed a memory error and can no longer process the instructions needed to run safely.
Your boiler has stopped working because its internal computer has detected a fault with its temperature sensors or the main control board.
Your boiler's internal control board has become too hot and has shut down the system to prevent any electrical damage.
Your boiler's control board is receiving an incorrect electrical signal from the flame sensor, meaning it cannot safely confirm if the burner is lit.
Your boiler has tried to start but could not create or detect a flame, causing it to shut down for safety.
Your boiler has failed to keep the flame lit and has locked itself out for safety.
Your boiler has got too hot and stopped working to protect itself, likely because the water isn't moving through the system properly.
Your boiler has lost its ability to measure the temperature of the water leaving the unit, usually due to a faulty sensor or a wiring issue.
Your boiler has lost signal from the sensor that monitors the temperature of the water returning from your radiators.
Your boiler's main internal computer is having trouble communicating with its electronic components, meaning it cannot process instructions to provide heat.
Your boiler's main control panel is having trouble communicating with the internal display or remote controls.
Your boiler's computer brain has encountered a serious communication error and can no longer control the heating system safely.
Your boiler has shut down because it has detected that the water inside is getting much too hot, which is usually caused by a circulation problem.
Your boiler thinks it still sees a flame even though it has commanded the burner to turn off, which is a safety concern that prevents it from restarting.
Your boiler has detected that the electrical supply coming into the unit is currently too low for it to operate safely.
Your boiler's control panel has lost communication with the internal system, preventing you from adjusting settings or seeing the boiler's status.
Your boiler has lost connection with a temperature sensor, meaning it cannot safely monitor the heat of the water going to your radiators.
Your boiler's internal computer chips are unable to communicate properly due to a software version mismatch.
Your boiler has shut down because the water returning from your radiators has become too hot, usually due to a lack of water flow through the system.
Your boiler is heating up too quickly, causing it to shut down to prevent damage from overheating.
Your boiler has detected that the water is heating up far too quickly or there is a blockage preventing hot water from flowing out of the unit.
BoilerFaultCodes