Select a fault code
The boiler has failed to ignite. Common causes are low gas pressure, a faulty ignition electrode, or a blocked condensate pipe.
The flame went out during normal operation. This can be caused by gas pressure fluctuations or a draught.
The boiler has overheated and the safety thermostat has activated. Causes include blocked heat exchanger or poor circulation.
Gas pressure at the boiler is insufficient.
The flow temperature sensor has failed or is reading incorrectly.
The return temperature sensor has failed or is reading incorrectly.
The fan is not running at the correct speed for safe combustion.
The air pressure switch has not confirmed fan operation before ignition.
A fault has been detected on the gas valve.
An internal fault on the main circuit board.
The boiler has locked out after multiple failed ignition attempts.
The condensate drain is blocked or frozen.
Flame detected when the burner should be off. Serious fault.
The domestic hot water temperature sensor has failed.
The system water pressure has dropped below the minimum operating level.
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