I'm not real skilled with forums, but had difficulty finding specific help in replacing the 30 year old Hydro Flame furnace in our 1988 Argosy. Perhaps this will help someone else. First, these guys were great in explaining the 3 layers of safety that could be causing the problem:
https://youtu.be/N-zqTLjG7qA. Rather than waste time and money replacing sail switch, limit switch, circuit board, fan motor, etc., I decided to just get a new unit. Yes, they're pricey ($570), but it's hard to put a value on comfort and safety in a 30 year old RV. Several forum entries seemed to assume we needed a new Suburban NT30SP, but when I took my unit out, the measurements were different (mine were 16.5" wide, 7" high, and 18" deep). My new unit manual says specifically that it can be operated in either horizontal or vertical position, but it fits perfectly into the old space (it was actually 20" long which required moving the wood platform back a couple inches to support the unit). As to vendors, I went with AdventureRV.net in the Knoxville area, and couldn't be happier. They managed 2 day delivery during New Year's week for an Atwood Model AFM1230111. The only difference besides being 2 inches longer was that the propane fitting is accessed from above, not the side. This was a simple change. So far, the new unit is working quietly and effectively. Make sure the "off/reset" switch is in the "on" (reset) position. Also, the wiring harness has red/white wires, and the furnace comes with red/black. Just match red-red and white-black.
Linear Mode
