This is interesting...I had my furnace installed in Feb. 1996 and the heat exchanger is gone bad on it also. I have been on a few other websites and have seen this same situation repeatedly. I was not aware of the fact that my heat exchanger was under warrranty until a friend of mine told me about his furnace. I think this really should be looked at closely. I would like a refund if this turns out to be a recall on this item.