> Just a single unit failure (I think) but the fraser-johnson furnace we had
> put into our last house self destructed its exhaust boost blower
I've heard lots of the earlier high-efficiency furnaces had similar weird
problems. Seems the designers just didn't think about what happens when you
cool flue gases that much. Friend of mine recently heard gurgling noises from
his ... turned out the condensate drain was plugged and the burner was literally
trying to run under water ! Odds are that any company still making them after
10-15 years will have most of the bugs ironed out.