Our manufactured home has a colman furnace and for heating it works fine. I would like to use the fan only mode when we have the fire place going but it is not hooked up, and I just want to make sure that i'm not going to fry anything.
On the circut board for the furnace there are two terminals labeled heat and cool. Those both go to the plug for the blower but only the heat is connected to one of the two wires going to the blower (the other wire connects to a neutral terminal).
When the heat is on, the heat terminal kicks on and provides power to the blower. When fan only mode is on the cool terminal is energized, but it is not hooked up to anything.