How much does it cost to fix boiler error code Error 12?

Typical repair cost for the boiler Error 12 fault is £120-220 including labour.

Error 12 High

Boiler Fault Code Error 12

Also written as ERROR12 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Error 12 appears across 1 boiler brand and 8 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 a small internal fuse that protects its main control system has blown, cutting off the power needed for it to operate. (As reported on Atag E32S)

Pick your boiler brand for the Error 12 fix

Atag Error 12 8 models

Source

Information for the Error 12 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