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

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

EF High

Worcester Bosch EF Fault Code

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

Your boiler has detected that the water temperature is rising far too quickly for the amount of gas being used, which suggests water is struggling to circulate properly.

The Worcester Bosch EF fault code means: your boiler has detected that the water temperature is rising far too quickly for the amount of gas being used, which suggests water is struggling to circulate properly.. It appears on 2 Worcester Bosch models in our database.

Technical description: Central heating, boil detect. Large delta T despite minimum burner.

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 EF fault code

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

Source

Worcester Bosch 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 27 April 2026