How much does it cost to fix Worcester Bosch error code Terminals 8-9?

Typical repair cost for the Worcester Bosch Terminals 8-9 fault is £90-180 including labour.

Terminals 8-9 High

Worcester Bosch Terminals 8-9 Fault Code

Q: What does the Worcester Bosch Terminals 8-9 fault code mean?

Your boiler has lost the vital communication link with its external controls or safety thermostat, meaning it cannot receive the signal to turn on.

Also written as TERMINALS89 — same fault.

The Worcester Bosch Terminals 8-9 fault code means: your boiler has lost the vital communication link with its external controls or safety thermostat, meaning it cannot receive the signal to turn on.. It appears on 1 Worcester Bosch model in our database.

Technical description: not shorted at connector ST7

Typical repair cost £90-180 (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 Terminals 8-9 fault code

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

Greenstar i Repair: £90-180

Source

Worcester Bosch Terminals 8-9 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