Boiler Fault Code I.93

Also written as I93 — same fault.

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

Fault code I.93 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 has detected an internal communication issue between its electronic parts, which prevents it from operating correctly. (As reported on Viessmann Vitodens 222-F B2TF)