we replaced a cast-iron gas unit with a stainless steel unit when the after years of extreme wear the ci unit developed a crack. service man flagged it as unsafe.
we walked, we talked and took bids and discussed all the issues with furnace salesmen who all drove new trucks and talked like they knew it all. and maybe they did.
anyways we settled on an updated trane in both the air conditioner unit and high efficiency gas furnace. we kept our wood heater, just in case.
i think one of the issues now is parts: who makes them, who supplies them, and how much do they cost?
with global warming, maybe the furnaces will become obsolete soon enough.
