BoilerFaultCodesYour boiler has detected a sequence error or a flame signal where there shouldn't be one, causing the burner to shut down completely for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Burner control switches to lockout
What causes this fault?
This fault occurs when the boiler detects a persistent flame signal even after the burner should have switched off, or if the internal electrical checks fail during start-up. The most common reason is a build-up of carbon or moisture on the ionisation probe, which tricks the system into thinking a fire is still burning. In some cases, a fault within the main control board or damaged ignition wiring prevents the boiler from safely managing the combustion process.
This fault can be more frequent in autumn or winter when increased condensation or dampness in the air can affect sensitive electrical components and probes.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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