How much does it cost to fix boiler error code Lock-out signal lamp ON?

Typical repair cost for the boiler Lock-out signal lamp ON fault is £150-250 including labour.

Lock-out signal lamp ON High

Boiler Fault Code Lock-out signal lamp ON

Also written as LOCKOUTSIGNALLAMPON — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code Lock-out signal lamp ON appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is failing to detect that the flame has lit, causing it to shut down for safety reasons to prevent a build-up of unburned gas. (As reported on Biasi Riva Compact HE M96a)

Pick your boiler brand for the Lock-out signal lamp ON fix

Biasi Lock-out signal lamp ON 2 models

Source

Information for the Lock-out signal lamp ON fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

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