Boiler displays flame loss during operation, repeated ignition attempts then lockout

Safety first: Turn off gas and power before any internal inspection. Only qualified personnel should work on combustion components.

• Check gas supply stability: If other gas appliances also cut out, contact your gas supplier.
• Reset and observe: Reset the boiler and watch the sequence: fan, ignition clicks, flame, then shutdown. Note at which stage it fails.
• Do not clean electrodes yourself unless competent: The ionisation electrode and burner require careful cleaning and reassembly to manufacturer specifications.
• Call a Nibe technician: They will clean or replace the Nibe ionisation electrode, check burner pressure, and verify combustion using a flue gas analyser.