How much does it cost to fix boiler error code C15?

Typical repair cost for the boiler C15 fault is £150-250 including labour.

C15 High

Boiler Fault Code C15

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code C15 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 detect the movement of water inside the system, which is preventing it from heating your radiators or hot water properly. (As reported on Atag Premier)

Pick your boiler brand for the C15 fix

Atag C15 1 model

Source

Information for the C15 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