Technical description
The burner fails to ignite after five attempts, the device does not start up and switches to “Fault”.
What causes this fault?
This fault occurs when your boiler attempts to fire up but cannot detect a stable flame after several attempts. The most common reasons are a lack of gas reaching the unit, a worn-out spark plug that cannot ignite the fuel, or a internal sensor that is too dirty to 'see' the flame correctly.
In freezing temperatures, this code can be triggered if your external gas meter regulator or condensate pipe freezes, physically blocking the boiler's ability to operate.
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.