How much does it cost to fix Worcester Bosch error code 341 D4?

Typical repair cost for the Worcester Bosch 341 D4 fault is £150-350 including labour.

341 D4 High

Worcester Bosch 341 D4 Fault Code

Q: What does the Worcester Bosch 341 D4 fault code mean?

Your boiler is overheating because the water inside cannot circulate fast enough to move the heat away, so the system has safely shut itself down to prevent damage.

Also written as 341D4 — same fault.

The Worcester Bosch 341 D4 fault code means: your boiler is overheating because the water inside cannot circulate fast enough to move the heat away, so the system has safely shut itself down to prevent damage.. It appears on 2 Worcester Bosch models in our database.

Technical description: CH: supply and/or return temperatures rising too fast

Typical repair cost £150-350 (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 341 D4 fault code

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

Source

Worcester Bosch 341 D4 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