306 FA Emergency

Worcester Bosch 306 FA Fault Code

Also written as 306FA — same fault.

The Worcester Bosch 306 FA fault code means: your boiler has detected a flame signal even though it has commanded the burner to turn off, indicating it cannot safely confirm the fire has gone out.. It appears on 3 Worcester Bosch models in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: Ionisation detected after burner stop
Typical repair cost £180-350 (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 306 FA fault code

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

Source

Worcester Bosch 306 FA 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