Boiler Fault Code CONDITION 1

Also written as CONDITION1 — same fault.

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

Fault code CONDITION 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 a fault and has safely shut itself down to prevent damage, leaving you without heating and hot water. (As reported on Keston R-sm 20 FB)