BoilerFaultCodesTechnical description
Flame failed during burner operation
What causes this fault?
This fault occurs when the boiler's control system loses the signal that a flame is present while it is supposed to be firing. The most common reasons are a dirty or worn sensor that can no longer 'see' the flame, or an unstable gas supply that causes the flame to flicker and go out. It can also be triggered if the burner is struggling to breathe due to a blocked flue or a build-up of debris inside the heat exchanger.
This fault is more common in winter, as extreme cold can cause the condensate pipe to freeze, backing up water into the boiler and extinguishing the flame.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.