Technical description
Interruption of gas supply or ignition failure (spark at ignition electrodes for up to 5 seconds and for 3 attempts)
What causes this fault?
This fault occurs when the boiler fails to detect a flame after several attempts to spark, causing the system to shut down for safety. The most common reasons are a temporary interruption in your gas supply, a build-up of carbon on the ignition probes, or a component failure that prevents gas from flowing correctly into the burner.
This fault is frequently seen during extreme cold snaps, as the external condensate pipe can freeze and back up, preventing the boiler from lighting.
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.