FA 306 Emergency

Worcester 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 8 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: False flame error Reset button Flame detected after burner stop
Typical repair cost £150-300 (including labour)

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 →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like FA 306: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Worcester Bosch models that show the FA 306 fault code

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

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 7 July 2026