High Lockout
30 on Glow-worm EnergySaver Combi

Your boiler detects a flame when it shouldn't, which is causing it to shut down for safety.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

There is a flame signal without there being a flame present.

What causes this fault?

This fault occurs when the boiler's internal sensor incorrectly detects a flame after the burner has been told to switch off. This is most commonly caused by a carbon-coated or damaged sensing probe sending a false electrical signal, or a moisture-damaged control board misreading the system's status.

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.

Find a Gas Safe engineer
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