High
Lockout flame signal on Halstead Finest Gold

Your boiler has stopped working because it cannot detect a flame, meaning it is currently unable to safely heat your home or water.

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.

What the manual says

Manufacturer manual

No flame signal on ignition, or loss of signal during operation • Check detection electrode/lead • Check gas supply • Check gas valve and lead • Check PCB/spark generator

From this model's manual
Verified against the Halstead Finest Gold installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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