364 FA Emergency

Worcester Bosch 364 FA Fault Code

Also written as 364FA — same fault.

The Worcester Bosch 364 FA fault code means: your boiler has detected that a safety valve responsible for controlling gas flow is not closing correctly, so it has safely shut itself down to prevent a potential gas leak.. It appears on 2 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: Gas valve EV2 leak test failed
Typical repair cost £250-450 (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 364 FA fault code

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

Source

Worcester Bosch 364 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 7 July 2026