Boiler Fault Code F.065

Also written as F065 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code F.065 appears across 1 boiler brand and 3 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 its internal computer is getting too hot and has shut itself down to prevent damage to the internal wiring and controls. (As reported on Vaillant ecoTEC Plus 836)