How much does it cost to fix boiler error code 89?

Typical repair cost for the boiler 89 fault is £120-220 including labour.

89 High

Boiler Fault Code 89

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 89 appears across 5 boiler brands and 18 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's hot water sensor has stopped working, meaning it cannot accurately tell the system the temperature of the water, so it has shut down to prevent damage. (As reported on Ideal Logic Code Combi ESP1)

Pick your boiler brand for the 89 fix

Alpha 89 6 models Biasi 89 4 models Ideal 89 5 models Keston 89 2 models Viessmann 89 1 model

Source

Information for the 89 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 7 July 2026