Furnace problem may not be in the furnace!

[turkeychuckt]

I had an interesting day yesterday! Spent all morning chasing a furnace problem in my newmar mountain aire and learned some interesting things! First of all, I dont claim to be an expert but have worked on this Motorhome for the past 5 years. The problem started Sunday after the ice storm went through. I called a repairman out after I exhausted all possible blown fuse issues etc. It was not the furnace that was not working ! It turns out Newmar runs the thermostat through the A/C unit control panel on top of the Motorhome! We traced it down to the the control panel after replacing a relay on the side of the furnace and that did not fix it. (however, it did fix my arctic package). Newmar has a panel inside the a/c unit (Duotherm heat pump) that controls the a/c and the furnace. We came to this conclusion by twisting the output wires together on top and the furnace came on.
I suspected the panel at that point because I remember in the early fall we had a problem of the fan on the a/c unit shutting off before the compressor. My repair guy says it is that panel! I will wait for the ice to thaw and warmer weather to tackle that one! Right now, we wired in a temporary 2 wire mechanical thermostat to get by until then. He tells me only an authorized Duotherm outlet like camping world can order the board and I need all the numbers for that from the 5 button thermostat and the control panel under the A/C shroud.! Hope no one else has this problem and has to spend $300+ dollars to track it down like I did!

[MonacoMama]

I might suggest that your poll also include n"no problem" too!

[Route 66]

This is not unique to Newmar.

Dometic makes the entire control system, ACs, and 5 button Comfort Control Center and many RV manufacturers use this system.

[Gary RVRoamer]

The Atwood Comfort Control System thermostat uses a remote (called a Zone Control module) to actually control the furnae and a/c, especially where the furnace is tied to the heat pump (auto switches to furnace if heat pump can't do the job). The unit you saw in the a/c enclosure was probably the zone control. There is also a freeze sensor in the a/c coils to help identify when the heat pump or a/c freezes up and needs to be cycled off for a few minutes to defrost.