BoilerFaultCodesWorcester Bosch FA 306 Fault Code
Also written as FA306 — same fault.
The Worcester Bosch FA 306 fault code means: your boiler has detected a flame signal when it should be switched off, which means the safety system has locked out the unit to prevent it from operating until it is checked by a professional.. It appears on 14 Worcester Bosch models in our database.
Technical description: False flame error Reset button Flame detected after burner stop
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Worcester Bosch models that show the FA 306 fault code
Click a model for the full fault code list and model-specific repair notes.
- 24 RSF Repair: £120-£350
- 26 CDi Xtra Repair: £120-£350
- 30i Junior Repair: £120-350
- 35 RSF Repair: £120-350
- Danesmoor Repair: £120-350
- Greenstar 12i System Repair: £150-300
- Greenstar 12i System Repair: £150-250
- Greenstar CDi Compact Repair: £150-300
- Greenstar i Repair: £150-300
- Greenstar i Repair: £150-300
- Heatslave Repair: £120-350
- Hideaway Repair: £120-350
- Junior 24i Repair: £120-350
- Junior 28i Repair: £120-£350
Source
Worcester Bosch FA 306 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