It's cold weather time again and I thought I would pass on something I discovered last year. It's especially helpful for anyone using the gas furnace.
For the last two years, we have wound up wintering in cold climates, including a blizzard and -10 in South Dakota (long story).

We will be in a cold climate again this year in Northern Arizona but at least not as bad as last.

In any case, last year it was driving me nuts ~ when the Electric heat was on with the heat pumps using the overhead ductwork, the displayed temp on the thermostat was always pretty accurate to with a degree of what the actual ambient temp in the room was. if, however, we switched to gas for the furnace, after an hour or so the display on the thermostat would show a few degrees warmer than the room actually was. Drove me crazy setting and resetting thermostat turn on point. Was getting ready to change thermostat and was also looking at house ones because I figured the Coleman one was junk, etc ....

Was doing something else and happened to put my hand on the wall about 2 feet below the thermostat and it was warm .... moved my hand farther down the wall and it got warmer as I got closer to the steps and the basement.

Did a bit of thinking and reasoning and came to the conclusion that since the basement is heated when the furnace is on, there was enough warm air rising up into the wall behind the thermostat to screw up it's internal thermometer.

Fix is easy ~ at least on a RL and RE, you'll have to see how yours is mounted in other models. I removed the switch panel under the thermostat, cut a piece of 3" foam the right size and stuffed it into the wall under the thermostat to insulate it from any heat rising up the wall.

Works like a champ !! Thermostat is now always within 1 degree of ambient and furnace kicks on and off like it should. Happy (and warm) campers.

Hope this helps anyone else who winters. Btw, for anyone wondering, our coach has been in -10 degrees, 30 mph winds and 2 feet of snow and did just fine.

Good to know. It will be in the teens for part of this week.