How much does it cost to fix boiler error code Lock-out (Red neon)?

Typical repair cost for the boiler Lock-out (Red neon) fault is £120-250 including labour.

Lock-out (Red neon) High

Boiler Fault Code Lock-out (Red neon)

Also written as LOCKOUTREDNEON — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Lock-out (Red neon) 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 has stopped working because the flame inside failed to light or stay on. (As reported on Grant Vortex)

Pick your boiler brand for the Lock-out (Red neon) fix

Grant Lock-out (Red neon) 1 model

Source

Information for the Lock-out (Red neon) 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