Thermostat hysteresis

[gmisek]

We have a 2016 38GK with a RVproducts.hp thermostat. When using the furnace for heat when outside temps dip below 40degress F the furnace seems to cycle frequently. Does anyone know if there is a way to change the thermostat hysteresis so it does not cycle as frequently. I understand this will cause it to get cooler before the furnace comes on, but with as noisy as this furnace i,s that is preferable to the frequency of cycling currently taking place.

[xtasee]

I am sure others will chime in but on mine, below 40 degrees the electric heat through the heat pumps in the ac would become inefficient and it would demand the gas furnace. Are you talking about the heat pump in the ac unit?

Below 40 I would choose the propane setting. If you are talking about the gas furnace you can ignore me....

[gmisek]

I am referring to the propane setting; that is why I used the term furnace and not heat pump. When using the heat pump (above 40 degrees) it does not cycle near as frequently as using the propane furnace. I realize the cold temps make a difference but would still like to change the hysteresis if possible so it is less sensitive.

[Goat]

I don't know what temp swings you're getting with your t-stat, but mine is about 2 degrees below the set point when it comes on quite often. It will usually shut off at set point, but occasionally goes one degree higher. Depending on the outside temp and wind speed, it can be off for less than 2 minutes before the fan kicks in and furnace starts. It may run close to eight minutes before fan stops again. I have seen RV t-stats replaced with Honeywell programmable. As long as the replacement has batteries for power, the 12 volt/24 volt issue is no longer an issue.

[xtasee]

I did a couple of searches for something I had seen on here before. One of our members found he was getting heat up the inside of the wall under the thermostat causing a similar issue. I believe he took out the switch panel and insulated inside the wall blocking the heat that was going up and shutting off the t-stat. I am thinking it was Vaughn (piper guy).

I could not find the post but hopefully someone will remember it and copy it here for us.

[xtasee]

Found IT!! This is what Piper Guy Posted hope it helps

Thermostat Heat tip
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, not planning to be, 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.
__________________

[gmisek]

My experience is similar to what Goat mentioned. I just find in annoying for the furnace to come back on just two mins. after shutting down. Luckily in this unit we do not have an issue like Piper had. I appreciate everyones input, but still find it frustrating that the less expensive 5th wheels allow you to modify the thermostats hystersis.