I have a Janitrol furnace FVS120-85. Yesterday after a normal heat cycle the blower did not turn off. The blower is still running now. When there is a call for heat, the burners light and we get heat just like normal but when the heating cycle is done, the blower will stay on. I have checked for loose and broken wires, obstacles and debris but things are clear. Any suggestions where I should look next?

Usually the blower relay or the blower fan and limit control is the problem.

BTW the model # posted is incorrect. This number not listed in any electronic catalogues.

That number is the Size number. I could not find a model number. I tapped the limit control relays and the motor stopped but the transformer started to hum and I tapped that too and it stopped. It has run a couple of cycles now normally but I got a feeling I am going to have to replace something soon.

Probably the relays and if there on a circuit board you will have to replace the entire circuit board.

The model number will be on the furnace tag on the inside of the furnace door usually located on the face or side of the furnace itself right behind the door. You will need the exact model number for parts.