Boiler Fault Code Microprocessor faulty

Also written as MICROPROCESSORFAULTY — same fault.

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

Fault code Microprocessor faulty 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 The computer that controls your boiler is experiencing an internal error, which means the system cannot safely start or regulate your heating and hot water. (As reported on Ferroli Econcept 100)