Technical description
Flame Loss
What causes this fault?
This fault happens when the boiler successfully starts up, but the flame goes out shortly after because the system can no longer detect it. The most common reasons are a lack of gas entering the unit, a dirty sensor that can't 'see' the flame, or a blockage in the pipe that carries away waste liquid.
This fault is frequently seen during freezing winter spells, as the external condensate pipe can freeze solid and cause the boiler to shut down for safety.
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.