BoilerFaultCodes UA-65 High
Boiler Fault Code UA-65
Also written as UA65 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code UA-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's main control board is currently unable to communicate with its internal memory chip and needs a software or hardware synchronisation. (As reported on Daikin D2CND)
Pick your boiler brand for the UA-65 fix
Source
Information for the UA-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