How much does it cost to fix boiler error code H9-01?

Typical repair cost for the boiler H9-01 fault is £90-160 including labour.

H9-01 Low

Boiler Fault Code H9-01

Also written as H901 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code H9-01 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 is struggling to understand the outdoor temperature, which may cause your heating to run less efficiently or at the wrong temperature. (As reported on Daikin D2CND)

Pick your boiler brand for the H9-01 fix

Daikin H9-01 1 model

Source

Information for the H9-01 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