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

Typical repair cost for the boiler Safety lock-out fault is £80-120 including labour.

Safety lock-out High

Boiler Fault Code Safety lock-out

Also written as SAFETYLOCKOUT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Safety lock-out appears across 2 boiler brands 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 has detected trapped air bubbles that are preventing it from running safely, so it has shut down to protect itself. (As reported on Saunier Duval Sylva)

Pick your boiler brand for the Safety lock-out fix

Potterton Safety lock-out 1 model Saunier Duval Safety lock-out 1 model

Source

Information for the Safety 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