Burner Lockdown High

Worcester Bosch Burner Lockdown Fault Code

Also written as BURNERLOCKDOWN — same fault.

The Worcester Bosch Burner Lockdown fault code means: your boiler has stopped working because it cannot light the gas needed to create heat, often due to an ignition or sensor failure.. It appears on 1 Worcester Bosch model 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: No flame seen through spy glass, no spark across electrodes, or flame sensor/wiring fault.

What causes the Worcester Bosch Burner Lockdown fault?

This fault occurs when the boiler attempts to ignite but fails to detect a steady flame after several tries. The most common reasons are worn-out ignition sparks that can no longer light the gas or a layer of carbon buildup on the sensor that prevents the boiler from 'seeing' the flame even if it is actually lit.

Typical repair cost £120-280 (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 Burner Lockdown fault code

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

Source

Worcester Bosch Burner Lockdown 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 27 April 2026