Select a fault code

Boiler failed to ignite within the safety cut-off period. Gas supply issue, faulty electrode, or gas valve problem.

Flame lit initially but then extinguished — gas pressure drop, faulty flame sensor, or draught.

Primary circuit temperature exceeded the safety limit — pump failure, blockage, or very low flow rate.

Flame sensor detecting a signal when the burner should be off — faulty ionisation rod or gas valve leaking.

Fan not running, flue blocked, or air pressure switch not making contact.

System pressure below minimum operating level.

Flow NTC thermistor open circuit or short circuit.

Return NTC thermistor failed or disconnected.

Domestic hot water plate heat exchanger sensor fault.

Condensate drain pipe blocked or frozen, preventing condensate from draining.