345 EF High

Worcester Bosch 345 EF Fault Code

Also written as 345EF — same fault.

The Worcester Bosch 345 EF fault code means: your boiler has detected that no heat is being transferred into your radiators or hot water pipes even though the system is trying to fire up.. It appears on 2 Worcester Bosch models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Supply and/or return temperatures do not change after burner start
Typical repair cost £180-350 (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 345 EF fault code

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

Source

Worcester Bosch 345 EF 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