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

Typical repair cost for the boiler AC fault is £180-£450 including labour.

AC High

Boiler Fault Code AC

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code AC appears across 1 boiler brand and 22 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's internal computer is having trouble communicating with one of its main control parts, meaning the system cannot run. (As reported on Worcester Bosch Greenstar 25 HE Combi)

Pick your boiler brand for the AC fix

Worcester Bosch AC 22 models

Source

Information for the AC 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