Select a fault code

Boiler failed to ignite within the safety period. Gas supply interrupted, faulty ignition electrode, or gas valve fault.

Flame signal detected when no ignition has been requested — ghost flame from a faulty ionisation rod or PCB.

Multiple failed ignition attempts. Gas supply, igniter, or gas valve fault.

Primary heat exchanger temperature exceeded safe limit. Caused by low system pressure, pump failure, or blocked heat exchanger.

Fan not reaching the required operating speed. Fan motor failure or obstruction.

System pressure has dropped below the minimum operating threshold (typically 0.5 bar).

Condensate pipe blocked or frozen, preventing condensate drainage from the boiler.

Flue gas temperature sensor reading above the permitted limit. Possible flue blockage or recirculation of flue gases.

Domestic hot water inlet thermistor has failed or is disconnected.

Central heating flow temperature sensor open circuit or short circuit.