NT30A Startup fail

[Al and Missy]

Congratulations, David, on a fine troubleshooting job. There is a wire, probably brown, that comes in to the furnace from the battery negative post. It is probably connected to the case of the furnace somewhere. Current leaves the battery positive post, goes through the various circuits, then through a brown wire to the case of the furnace and finally through the brown wire from the case back to the negative post of the battery. Any wire with a lug connected to the case is suspect. Pull them all and clean the lugs and the case before reassembling them.

All of these furnaces have a similar risk. Propane is burned in a combustion chamber which is typically an inner metal tube surrounded by an outer metal tube the inside air flows through. The two are isolated by flanges and gaskets. If the common wall or a gasket fails combustion products can reach the interior of the trailer. The older the furnace, the more likely it is that a failure will occur.

Similarly, propane is burned in the rear of your refrigerator. When installed the refrigerator is supposed to be bedded in sealant to isolate the outside compartment from the inside of the trailer. You may wish to be observant in renovating around the fridge and installing your replacement unit.

Al

[2002sheds]

Hi Al,
Thanks for the kind words! And thanks also for your help over in the refrigeration section -- it is very helpful that people such as yourself offer their experience and advice to us newcomers!
I definitely hear you about sealing the refrigerator. I was reading the manua, and you are quite correct -- they want a good barrier between inside and out. I can understand why.
Regarding the furnace, I will clean up all of the terminals and connections, as you advised. I will also be wary of any sign of changes in its health, and get rid of it at the first sign of trouble.
I never did pin down the exact model number of this thing. My best guess is NT-22, based on the existence of the crossover tube (which is in good condition and further sealed with RTV). Dremel wrote in to say that their 1969 Ambassador is outfitted with a NT-30, so maybe that is the right one. I may do one last post on this thread and include a picture of a wiring diagram with the colors that correspond to this furnace, in case it is useful to someone.


Thanks Again!
David