26 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Keston System 2
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Your boiler has detected that the water temperature inside the system has become dangerously hot and has shut itself down to prevent damage.
Your boiler has detected that the water returning to it is dangerously hot, causing it to shut down to prevent internal damage.
Your boiler has detected that hot water is moving in the wrong direction or the sensors are misreading the temperature, causing the system to stop working to protect itself.
Your boiler is overheating because water isn't moving through the system fast enough, likely due to trapped air or a blockage.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Your boiler has stopped working because it cannot communicate with the internal air circulation fan, meaning it cannot safely clear waste gases.
Your boiler is struggling to communicate with its internal air-moving mechanism, meaning it cannot safely start up to provide heat or hot water.
Your boiler is struggling to move water around your heating system properly, causing it to overheat because the hot water isn't getting away from the heat exchanger fast enough.
Your boiler is pausing because it is not receiving the signal that the internal fan is spinning correctly to clear exhaust gases.
Your boiler has detected that the water inside the system has become dangerously hot or the water pressure is too low, causing it to shut down to prevent internal damage.
Your boiler has detected a flame at the wrong time and has shut down as a safety precaution.
Your boiler has attempted to start but failed to light the flame, so it has safely shut itself down to prevent a build-up of unburnt gas.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler has detected that it was turned off and back on again while it was already trying to recover from a previous unknown safety error.
Your boiler's internal computer has encountered a critical error and needs to be reset or potentially replaced to get your heating and hot water working again.
Your boiler has detected that it is dangerously hot and has shut down to protect your home from potential damage.
Your boiler has detected that the water inside it is getting dangerously hot because it cannot move around your heating system properly.
Your boiler has shut down because the water returning from your radiators is too hot, which usually means the water isn't moving through your heating system correctly.
Your boiler is struggling to move water around your heating system quickly enough, which is making it overheat internally.
Your boiler has stopped working because the mechanical part responsible for moving air through the system is failing to spin.
Your boiler is struggling to move water around your heating system, causing the water leaving the boiler to be much hotter than the water returning to it.
Your boiler has stopped working because it is unable to accurately read the temperature of the water flowing through it due to a faulty sensor or loose wiring.
Your boiler has detected a faulty temperature sensor reading on the pipe that carries water back from your radiators, which prevents it from heating your home correctly.
Your boiler has lost the signal from the sensor that monitors your heating water temperature, so it has shut down to prevent overheating.
Your boiler's temperature-sensing system has lost its connection, preventing the unit from accurately reading the water temperature and safely managing your heating.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
BoilerFaultCodes