High Lockout
Flame On Before Gas On on Ideal Logic Max Heat

Your boiler incorrectly thinks it sees a flame before it has even started the ignition process, which is a safety error that prevents it from starting up.

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

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What causes this fault?

This fault occurs when the boiler's control system detects an electrical signal suggesting a flame is already present before the gas has been turned on. The most common reason is a carbon build-up or moisture on the sensing electrode causing a false reading, or a communication error within the main circuit board.

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.

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