Atwood /Hydro Flame furnace replacement.
Got tired of the rear furnace sounding like it was going to self-destruct. My files showed "re-built 01", but no paperwork as to what that meant. Got a fresh one today, nervous whether it would fit after so many years. It did, but a pain in the tight quarters to remove/replace ducts. The propane connection was in a different place and I had to fabricate a new copper line. The flanges were not the same and they had to be modified, as well. All in all, blew a morning, thanks to some help from a friend that had a copper flairing tool. The new version is twice as strong ( BTU wise) and quiet as all get out. The only exterior change anyone would notice, would be the exhaust flange, where the new one did not fit and I modified the old one with rivets. Any one who considered my offer of a free furnace and passed, were right: once I looked inside that old dear, it was junk!