Temperature swings.

[Jpiercemt]

Hello everyone,
When I turn on my heater in my “new to me” 2013 Grandby, the temp gets really hot inside the camper before the furnace turns off. Then likewise, it gets pretty cold before it turns back on. Is this normal? Should I change out thermostat? Perhaps a digital model? Thank you!!

 

[Kolockum]

Nope. That is pretty much the nature of the beast. However most thermometers have some sort of adjustment for the type of heat, ie. radiant, forced air, etc. This adjustment narrows the gap between the high and low temps. Maybe play around with that.

 

[BBZ]

we found that we can't turn it up too high because of this, then we get too hot and then too cold.. we use the heater to keep it just warm enough to be comfortable under our down comforter.. we found 45-47 is perfect while sleeping.

 

[wicked1]

The thermostat in mine seems to be too large a thermal mass. Compared to the one in my home, it reacts to temp changes very slowly. I can blow hot air on it, and it won't increase the displayed temp for a couple minutes.
The thermostat in my home, I can literally just stand near it, and it will almost immediately raise 1/2 a degree.

So, in the camper, it might be 40. I set the thermostat to 50. It runs. Turns off when it hits 50. But the camper is actually quite a bit hotter. Over the next hour the camper begins to cool, but the thermostat read-out continues to increase.. Finally getting to about 58.. Then we have to wait for the camper to cool, and then the large thermal mass of the thermostat to finally cool back off. The camper is freezing cold, and the thermostat displays 55.. heat still set on 50.

I'm confident a different thermostat will greatly improve things in the camper.

My thermostat is a beige digital one, very basic.. Just heat on/off and up/down temp. I think it is a FWC factory part. (I'm the 2nd owner, so not 100% positive).

 

[Old Crow]

You might check whether your thermostat has an "anticipator".

This clip from an Atwood service manual describes the idea...

(Click to enlarge)



I took this photo of the Atwood mechanical thermostat this morning. The 'stat is from my 2001 Hawk. I was curious whether it would look like the one in the manual and it does not. But it's the same idea. The pencil points to the anticipator.

(Click to enlarge)

 

[Wallowa]

Be careful of what you ask for...you just might get it....a sensitive, quickly responding thermostat?

Yup, it will keep FWC at a more constant temperature; but at what cost?

My '16 Hawk, even with thermopak and other insulation I have added, does not retain heat very well and cools down quickly...if I had a quick responding thermostat that kept the Hawk at a set temp..with that high loss of heat to the outside, my furnace would need to cycle off and on almost continuously...using a ton of battery and propane..better for me to pump in heat and bundle up until a re-heat is necessary...it takes little time to raise inside temp and nets a saving of amps and propane..increasing tolerance to temp ranges and not running furnace as much works for us.

Just the way I do it and I could be wrong....

Phil

 

[PaulT]

I suspect that there is a thermal mass effect with the plywood cabinet that gets little to no heat within the cabinet with the furnace aiming its hot air across the camper. In my front dinette, the fridge door receives much more heat than does the cabinet containing the furnace & the thermostat. The thermal sensor seems to respond to the cold air within the cabinet more than the warmed air in the living space.

The heated air in the camper seems to get much warmer than the thermostat set point before the furnace cuts off.

I have considered placing a 1/8” foam sheet as a thermal break between the cabinet and thermostat and plugging the holes for the thermostat wires thru the plywood as a partial solution. Using something like the thin plastic foam wrapping used to protect electronics in shipping would be a cheap test.

Haven’t tried it yet because we usually just tolerate the cold air. We’re camping, after all. The only time it really bothers me is when it is below 40 in the camper while sleeping and the bladder alarm goes off.

Paul

 

[Stan@FourWheel]

Could be worth a try to switch it with a different thermostat.

Would only cost $15 - $25 for a try.

Best case it works. Worst case you have a newer thermostat and are only out a few bucks.

A good nights sleep is worth the cost for most customers.

Tech Tip: (Like Paul mentions above) Maybe try putting something on the back of the thermostat as well? See if you could put a piece of plastic, foam, spacer, or additional wood backing to help give it a better thermal barrier. Not sure if it would even help? But . . . inside the kitchen cabinets gets pretty cold at night, and if the thermostat is picking up some of the "cold" from the wood it's attached to because is also really cold, it might be throwing off the reading on the thermostat. You could even unscrew the thermostat, leave the wires hooked up, but let it dangle from the cabinet face for one night to see if that helps at all. A wild idea, but worth looking into if you are trying for a solution. I always try the easy thing first, even if they seem silly. And then tackle the more difficult solutions if the easier things don't do the trick.

 

[Jpiercemt]

Thanks for the tips everyone! I’ll give them all a try! I sure appreciate everyone’s advice on this forum, so incredibly helpful!