29 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: ecoTEC plus 937
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Your boiler has lost its connection to the temperature sensor that monitors water flowing through the system, preventing it from heating up safely.
Your boiler has stopped working because one of its internal temperature sensors is unable to send a signal, meaning the system cannot tell if it is safe to heat the water.
Your boiler's hot water sensor has stopped communicating with the main control board, meaning the system can no longer tell how hot your water is.
Your boiler has lost communication with the temperature sensor in its internal hot water storage tank, meaning it cannot safely monitor or heat your hot water.
Your boiler has detected an electrical fault with the internal sensor that monitors the temperature of the water flowing out to your taps and radiators.
Your boiler has detected an electrical fault with the sensor that monitors water returning from your radiators, often caused by a faulty part or damaged wiring.
Your boiler has detected a faulty sensor that monitors your hot water temperature, meaning it cannot safely heat water for your taps.
Your boiler's hot water storage tank sensor has developed an electrical fault, meaning the system can no longer monitor or control the temperature of your hot water.
Your boiler has switched itself off because it has reached an internal temperature that is too high, often caused by a blockage or poor water flow.
Your boiler has detected that there is not enough water pressure or flow to operate safely, causing it to shut down to prevent overheating.
Your boiler has detected that the water isn't moving through the system quickly enough, causing it to heat up too fast and shut down to prevent damage.
Your boiler is heating up too quickly because the water inside isn't moving fast enough, usually due to trapped air or a struggling pump.
Your boiler has detected a false flame signal or a communication error between the gas valve and the control board, preventing it from firing up safely.
Your boiler is failing to light the gas flame despite several attempts, meaning you currently have no heating or hot water.
Your boiler has lost its flame while running and cannot manage to relight itself, likely due to a problem with the gas supply.
Your boiler has stopped working because the fan is spinning at the wrong speed, causing the system to lock as a safety precaution.
Your boiler has stopped working because it cannot confirm that waste gases are being safely vented out of the flue.
Your boiler has stopped working because the fan that helps remove exhaust gases is not spinning at the correct speed.
Your boiler has lost its settings and doesn't know whether it should be burning natural gas or LPG, causing it to stop working for safety reasons.
Your boiler has detected an internal electrical wiring issue or a faulty connection that prevents it from running safely.
Your boiler has stopped working because its internal electrical wiring is either loose, damaged, or incorrectly configured.
Your boiler's internal computer has developed a fault and can no longer communicate with the gas valve or control the heating process.
Your boiler's main control computer or the gas valve connection has suffered an internal electrical failure, preventing the system from operating safely.
Your boiler is still detecting a flame even though it has commanded the gas to turn off.
Your boiler’s internal computer has encountered a communication error or electrical fault that is preventing it from running safely.
Your boiler has detected a communication error between its internal sensors and the main control board, preventing it from operating safely.
Your boiler's internal control board is overheating, causing the system to shut down to prevent damage.
Your boiler is having trouble communicating with its control screen, which means you cannot see or change its settings.
Your boiler’s internal computer has detected a communication error or a hardware failure within its control system, preventing the boiler from starting.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes