BoilerFaultCodesTechnical description
Ignition electrode and lead (faulty connection, spark gap or position), igniter failure, or gas supply issues.
What causes this fault?
This fault occurs when the boiler's control board attempts to start the burner but fails to detect a flame after several attempts. The most common reasons are a lack of gas reaching the unit, a worn-out ignition spark that can no longer light the fuel, or a dirty internal sensor that cannot see the flame even if it has successfully lit.
This fault is frequently seen during extreme cold snaps, as external gas regulators can freeze or condensation pipes can block, preventing the ignition process from completing.
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.