Boiler Fault Code F.97

Also written as F97 — same fault.

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

Fault code F.97 appears across 1 boiler brand and 12 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's internal computer has failed a self-test and is no longer able to communicate with the rest of the system. (As reported on Vaillant ecoTEC plus)