Boiler Fault Code 1 PILOT WILL NOT LIGHT

Also written as 1PILOTWILLNOTLIGHT — same fault.

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

Fault code 1 PILOT WILL NOT LIGHT appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's small starter flame is failing to ignite, which prevents the main heating system from starting up. (As reported on Ideal Classic RS)