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

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

Terminals 8-9 High

Boiler Fault Code Terminals 8-9

Also written as TERMINALS89 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Terminals 8-9 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has lost the vital communication link with its external controls or safety thermostat, meaning it cannot receive the signal to turn on. (As reported on Worcester Bosch Greenstar i)

Pick your boiler brand for the Terminals 8-9 fix

Worcester Bosch Terminals 8-9 1 model

Source

Information for the Terminals 8-9 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026