BoilerFaultCodes 12-65 High
Boiler Fault Code 12-65
Also written as 1265 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 12-65 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 having trouble starting the burner safely and needs a simple restart to clear a temporary electronic glitch. (As reported on Daikin D2CND)
Pick your boiler brand for the 12-65 fix
Source
Information for the 12-65 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