How much does it cost to fix Worcester Bosch error code 338?

Typical repair cost for the Worcester Bosch 338 fault is £150-300 including labour.

338 High

Worcester Bosch 338 Fault Code

Q: What does the Worcester Bosch 338 fault code mean?

Your boiler has repeatedly tried to start but failed to detect water movement, so it has locked itself out to prevent internal damage.

The Worcester Bosch 338 fault code means: your boiler has repeatedly tried to start but failed to detect water movement, so it has locked itself out to prevent internal damage.. It appears on 1 Worcester Bosch model in our database.

Technical description: Too many short burner starts without confirmation Reset button There is an error where the pump is not detecting water.

Typical repair cost £150-300 (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 338 fault code

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

Greenstar CDi Compact Repair: £150-300

Source

Worcester Bosch 338 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