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 £90-180 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 27 April 2026

Fault code Lock-out signal lamp ON appears across 1 boiler brand and 1 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 the flame after lighting, causing it to shut down for safety purposes even though the gas is ignited. (As reported on Biasi Riva Compact 24S)

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

Biasi Lock-out signal lamp ON 1 model

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 27 April 2026