A bad bearing in the draft motor or the blower motor that must be replaced A leak in the furnace cabinet, sheet metal plenum or ductwork near the furnace that must be tightened A dirty filter, which can also cause whistling 10. The Furnace Leaks when AC is Running ...
I figured the numbers would work out much better if I could actually do the replacement job myself, because a top-of-the-line gas furnaceonly costs about $1500online these days. But I didn’t know exactly how to do it and there never seemed to be a good time to learn*. Nobody I ...