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

Typical repair cost for the boiler 89 fault is £100-200 including labour.

89 High

Boiler Fault Code 89

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code 89 appears across 5 boiler brands and 20 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is struggling because the electrical supply wires have been connected the wrong way round, preventing the system from detecting a safe flame. (As reported on Ideal Isar HE)

Pick your boiler brand for the 89 fix

Alpha 89 6 models Biasi 89 4 models Ideal 89 5 models Keston 89 4 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 31 August 2026