Boiler Fault Code C1 10

Also written as C110 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code C1 10 appears across 1 boiler brand and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected that it is running much hotter than it should be and has automatically switched itself off to prevent damage. (As reported on Atag Q 25CR)