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

Typical repair cost for the boiler Lock-out signal lamp red (ON) fault is £120-250 including labour.

Lock-out signal lamp red (ON) High

Boiler Fault Code Lock-out signal lamp red (ON)

Also written as LOCKOUTSIGNALLAMPREDON — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Lock-out signal lamp red (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 even though the burner briefly ignites. (As reported on Biasi Riva Compact HE M96a)

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

Biasi Lock-out signal lamp red (ON) 1 model

Source

Information for the Lock-out signal lamp red (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