I have a Sears 600 pilot free wall furnace, model # 867 734680. I do not know it's age. This winter, when using the heat, the fan would occasionally not function. Unit would get hot, but no fan to blow the air. This summer, the fan was working OK to circulate the air, until recently. Now when I turn the unit on, I hear a buzzing, as if the fan wants to turn on, but does not.
Can you help me with this problem?