9F High

Worcester Bosch 9F Fault Code

The Worcester Bosch 9F fault code means: your oil-fired boiler has stopped working because the burner failed to start, which can be caused by a fuel supply issue, a blocked filter, or the boiler needing a service.. 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: Burner lock out. Check the burner and fuel supply.
Typical repair cost £150-350 (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 9F fault code

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

Source

Worcester Bosch 9F 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