Boiler Fault Code 2.2.1

Also written as 221 — same fault.

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

Fault code 2.2.1 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 or software issue, meaning it cannot properly monitor its own temperature rise and has safely shut down to prevent damage. (As reported on Baxi 825 Combi)