How much does it cost to fix Worcester Bosch error code b7?

Typical repair cost for the Worcester Bosch b7 fault is £250-450 including labour.

b7 High

Worcester Bosch b7 Fault Code

Q: What does the Worcester Bosch b7 fault code mean?

Your boiler's computer has detected a serious internal fault that prevents it from operating safely, requiring a qualified professional to inspect or replace the electronic control system.

Also written as B7 — same fault.

The Worcester Bosch b7 fault code means: your boiler's computer has detected a serious internal fault that prevents it from operating safely, requiring a qualified professional to inspect or replace the electronic control system.. It appears on 8 Worcester Bosch models in our database.

Technical description: Internal error - replace control board

Typical repair cost £250-450 (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 b7 fault code

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

Source

Worcester Bosch b7 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