Hi there,
Hoping someone may have some advice in this regard as I am stuck!!!
Our furnace runs fine with heat ON and fan to auto. I can't for the life of me get the fan to run on its own on ON. If I have heat to Off and turn fan to On both heat and fan come on! Only 3 wire system
Red to Red, White to White, Green to Green, no A/C. Thought fan relay on board was toast, replaced with new board, same issue.
Tried new stat as well with no luck.
Any ideas are greatly appreciated! We have a wood stove and I need to circulate air around house with fan.
Jump R to G on thermostat ..if fan comes on ..thermostat is bad..if not ..jump R to G on board ..if fan runs then you have an issue with G wire line from thermostat to board