BoilerFaultCodesTechnical description
Error during start-up or operation; followed by a 3 minute venting cycle
What causes this fault?
This fault occurs when the boiler's control system cannot detect a steady flame after trying to ignite several times. The most common reasons are a lack of gas reaching the burner, a build-up of carbon on the ignition parts, or a sensor failing to tell the boiler that the fire has successfully lit. This leads the unit to enter a safety venting cycle to clear any unburnt gas before it tries again.
This issue is more frequent during extreme cold snaps, as external gas meters can occasionally freeze or supply pressures can drop when local demand is at its peak.
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.