How much does it cost to fix Worcester Bosch error code FA 364?

Typical repair cost for the Worcester Bosch FA 364 fault is £280-£450 including labour.

FA 364 Emergency

Worcester Bosch FA 364 Fault Code

Q: What does the Worcester Bosch FA 364 fault code mean?

Your boiler has shut down because its internal safety checks detected that a gas valve isn't closing properly, which could lead to a small amount of gas escaping into the unit.

Also written as FA364 — same fault.

The Worcester Bosch FA 364 fault code means: your boiler has shut down because its internal safety checks detected that a gas valve isn't closing properly, which could lead to a small amount of gas escaping into the unit.. It appears on 11 Worcester Bosch models in our database.

Technical description: Gas valve EV2 leak test failed – gas valve leak

Typical repair cost £280-£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 FA 364 fault code

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

Source

Worcester Bosch FA 364 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