lock-out High

Worcester Bosch lock-out Fault Code

Also written as LOCKOUT — same fault.

The Worcester Bosch lock-out fault code means: 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.. It appears on 8 Worcester Bosch models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: The burner will go out but, after a short pause, the appliance will make 5 attempts to restart sparking for 5 seconds and then 'lock-out'. This occurs if the gas service cock is turned off or if the boiler fails to light after a maximum of 5 attempts.
Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Worcester Bosch models that show the lock-out fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch lock-out fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026