Lockout flame signal High

Halstead Lockout flame signal Fault Code

Also written as LOCKOUTFLAMESIGNAL — same fault.

The Halstead Lockout flame signal fault code means: your boiler has stopped working because it cannot detect a flame, meaning it is currently unable to safely heat your home or water.. It appears on 1 Halstead model in our database.

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: 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
Typical repair cost £150-300 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Halstead models that show the Lockout flame signal fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Halstead Lockout flame signal fault code information on this page is sourced and cross-checked against the official Halstead service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026