How much does it cost to fix boiler error code lock-out?

Typical repair cost for the boiler lock-out fault is £120-250 including labour.

lock-out High

Boiler Fault Code lock-out

Also written as LOCKOUT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code lock-out appears across 7 boiler brands and 31 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has failed to ignite after several attempts and has switched itself off for safety reasons, meaning it cannot currently provide heat or hot water. (As reported on Worcester Bosch Greenstar 15sbi)

Pick your boiler brand for the lock-out fix

Biasi lock-out 2 models Firebird lock-out 1 model Grant lock-out 16 models Halstead lock-out 1 model Heatline lock-out 2 models Vaillant lock-out 2 models Worcester Bosch lock-out 7 models

Source

Information for the lock-out 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