How much does it cost to fix boiler error code H.01 – .18?

Typical repair cost for the boiler H.01 – .18 fault is £120-£350 including labour.

H.01 – .18 High

Boiler Fault Code H.01 – .18

Also written as H0118 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code H.01 – .18 appears across 1 boiler brand and 24 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has stopped working because water is not moving through the system properly or a temperature sensor has detected an overheating issue. (As reported on Baxi 200 / 400 Combi)

Pick your boiler brand for the H.01 – .18 fix

Baxi H.01 – .18 24 models

Source

Information for the H.01 – .18 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