Our fan unit outside is doing nothing at all, no noise or anything, when I turn on the heat I feel a little bit of warm coming through the vents but its not blowing and only in a couple rooms not all so I was wondering if there was anything I could check or do to fix the issue without calling a pro, any suggestions would be really helpful! I even checked main breaker box and its fine, I turned fan to make sure it wasn't stuck and it turns, I looked outside and there is a box but it says it don't contain fuses but there is a black handle thing that you can pull out that has 4 prongs or something that sticks out of it that attatches to the box the unit is lennox, not sure if this info is helpful but that is just things I have already tried! Thanks