I have an old BDP Gas Furnace in my house. The fan started running continuously one afternoon and I traced the problem to the fan relay on the controller card.
Now, I have a little, actually quite a bit, of experience in Industrial AC units, centrifugal chillers mostly, so this one is really frustrating me and kicking my backside.
I purchased an ICM 271 controller card to replaces the 302075-3 card in the system. Followed the instructions on the enclosed sheet and when I place the system to heat, the fan starts but no heat. I labeled the wires and laid them down correctly, ran continuity checks because I had to replace a couple of wires and everything check from that prespective.
So I need some real heating professional help. I didn't cut the jumper or remove the R12 resistor, it wasn't removed on the original board.
Any and all suggestions/help is really appreciated.