BoilerFaultCodesTechnical description
False flame signal
What causes this fault?
This fault occurs when the boiler's sensors detect heat or electricity in the burner area at a time when the gas should be completely shut off. The most common reason is a carbon buildup on the internal probes or a moisture-related fault on the control board, tricking the boiler into thinking a fire is still burning. For safety reasons, the system will prevent the boiler from starting any new heating cycle until this is resolved.
This fault can be more frequent during periods of high humidity or heavy rain, as moisture ingress into the air intake can affect the sensitivity of the ignition components.
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.