LED3 on PCB 37 Low

Boiler Fault Code LED3 on PCB 37

Also written as LED3ONPCB37 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code LED3 on PCB 37 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 This light is actually a positive signal showing that your boiler's internal electrical fuse is working correctly and the control board has power. (As reported on Ideal Classic FF)

Pick your boiler brand for the LED3 on PCB 37 fix

Ideal LED3 on PCB 37 1 model

Source

Information for the LED3 on PCB 37 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

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