Thermostat warm-up

S

Stalking Light

Feral Grandpa
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I've noticed that it takes a good while for the thermometer in the thermostat to 'warm up' to the current room temperature when starting the furnace on a cold day, and the inside temperature can get very hot in the process. Apparently the cabinet it's mounted on is an efficient heat sink and it needs to be warmed up too, which I do by periodically shutting off the heat until things reach equilibrium.

Has anyone figured out a quicker way? It probably takes me 30+ minutes of cycling before I can let things alone.
 
IMG_0408.JPG

Mine came with a digital thermostat.
 
The thermometer reads in the 50's when the internal temp is around 70. I may just have to put a hot towel on it, or maybe I'll try a hand warmer packet.


billharr said:
Looks like it is next to the window. I put mine closer to the center of the camper.
Click to expand...
Not much room in my Eagle to move it to. It seems like the cabinet has to warm up before the thermometer reads correctly, so I don't think the front window is the issue.

Thanks for all the suggestions.
 
I have the same thermostat in my 2014 Hawk and have noticed a similar time lag to rising internal temp. I have an infrared thermometer and the fridge door across from the heater had reached 90+ temp while the thermostat still showed about 70. The area around the thermostat was a little higher than the thermostat indicated. Meanwhile the temp around my head while standing was in the 90 deg range.

I think that one has to manually control the temp until the thermal mass of the camper has warmed to near the target temp. The little furnace can really pump out the heat for the amount of air in the camper. Seems like a separate small fan like the O2 fans to circulate the heated air around the interior might be a big help especially if you aim it towards the floor or have the fan on the floor aimed to the ceiling to mix the air better.

Paul
 
PaulT said:
...I think that one has to manually control the temp until the thermal mass of the camper has warmed to near the target temp. The little furnace can really pump out the heat for the amount of air in the camper. ...
Click to expand...
This is my experience also. It is worse the colder it is. The cold coming through the wall to the back of the thermostat is part of the problem. We have a digital thermostat. I have thought of putting a bit of insulation behind the thermostat but I haven't done it yet. We just cycle the furnace by hand until things warm up.
 
KILR0Y said:
You should be able to go into the thermostat settings and adjust the hi/low settings. they control how many degree spread the stat will kick on and then back off...

Sent from my SM-G900P using Wander The West mobile app
Click to expand...
In most electronic thermostats they work off of 2 things one is temp. the other is time. The time is called cycle rate, Most come from the factory set at 5 cycles per hour. If you can adjust it try 9 cycles per hour, If is says stuff like gas,hot water or electric set it for electric which is 9 cycles per hour where hot water is 3 and gas is 5. If you can't adjust your cycle rate get rid of that thermostat and buy a Honeywell.
 
Charlie, I wonder what a piece of neoprene between the thermostat and wood would do. I've noticed the same issue in both the Grandby and Airstream. The wood where the thermostat is mounted takes a long time to come up to the heat setting.
 
I use a very small USB fan that I purchased at Campers World to break up the thermal layering. I converted one of the power point (cig lighters) to a duplex USB outlet purchased from West Marine that it plugs into. I also installed another one on the opposite side near the bed. These are also handy for charging various. The power draw is almost nil. It is silent and vibration free. It moves the air just enough to create a more consistent quality environ absent the thermal layering that happens in between furnace activation.
 
Kispiox said:
I use a very small USB fan that I purchased at Campers World to break up the thermal layering. I converted one of the power point (cig lighters) to a duplex USB outlet purchased from West Marine that it plugs into. I also installed another one on the opposite side near the bed. These are also handy for charging various. The power draw is almost nil. It is silent and vibration free. It moves the air just enough to create a more consistent quality environ absent the thermal layering that happens in between furnace activation.
Click to expand...
Sounds like a handy item, thanks.

I put a small piece of Reflectix behind the thermostat and will see if that helps.
 
Possibly, but mine works great when it gets warmed up. I think the cabinet is acting as a heat sink and it needs to be warmed up too, I'll see if the Reflectix changes the behavior any.
 
Stalking Light, did you ever resolve the issue of the thermostat's slow warmup? We have the same issue with our new Grandby. We have been checking it out getting ready for a trip but it just seems this is a strange way for the thermostat to work.

We were testing this morning (20 degrees outside) and it showed 41 on the thermostat after running the furnace for more than 15 minutes. I turned the furnace off then did the reset as indicated in the instructions and it immediately showed the correct temperature of 65 degrees. Later in the day we tested it and again it wouldn't show the correct temp until we did a reset. If it really was the cabinet acting as a heat sink it seems the reset wouldn't make any difference.

Just curious if you learned anymore about yours. Thanks!
 
Following this with interest. The relatively uninsulated cabinet holding the thermostat, and I assume the heat sensor, is in a poor place to register the temp in the camper but rather is more influenced by the cold coming in from the cabinet through the camper wall. In addition it is fairly low in the camper to measure temp above that level and of course heat rises.

Personally, I will go with the neoprene recommended by Sagebrush and skip the Reflectix. Radiant heat loss is not the problem; conductive and perhaps convective heat loss is keeping the heater thermostat lower than camper temp. The cabinet is a good insulator keeping the cold in and heat out away from the sensor. Eventually the cabinet will heat up and the senor will register temps closer to that level inside the camper.

Just my WAG and I could be wrong! :)

Phil
 
I would install a different thermostat, had a digital in another camper that I had and never had a problem with it. Believe it was a Hunter brand. Ron
 
Thanks for the replies.

Wallowa (my old home town!):

"The relatively uninsulated cabinet holding the thermostat, and I assume the heat sensor, is in a poor place to register the temp in the camper but rather is more influenced by the cold coming in from the cabinet through the camper wall. In addition it is fairly low in the camper to measure temp above that level and of course heat rises."


We initially thought the same thing but now I'm not so sure. I just ran another test using a second thermometer (#2). I dropped the sensor into the cabinet that holds the thermostat (#1) then turned the furnace on. After 20 minutes or so, #2 was registering 50 degrees and #1 hadn't made it up to 30. I suppose that could be explained if the #1 sensor is buried inside the cabinet wall or something but that would be really poor design IMHO.

What this doesn't explain is what happens when I turned the furnace off at 50 degrees, let it shut completely down then did the reset (hold both arrow buttons in and push the Heat switch to on). When I did that #1 instantly reset itself and matched the temp displayed by #2. It shouldn't do that if the actual temp at the sensor of #1 was less than 30.

Maybe a replacement is in order.
 
You may in fact have a bad thermostat. Mine eventually catches up to the air temp and stays that way, so mine seems to be working fine. I've not tried resetting my thermostat, I just turn the heat off for a while if the air temp gets too hot during the initial warm up.

It's been a number of years since I had any thermodynamics courses, but my working theory was that the sensor was just too close to the cabinet heat sink and adding the Reflectix helps isolate it. That does seem to be the case in my instance. Reflectix is basically mylar sandwiched around bubble wrap, so it does more that just slow radiant heat transfer.
 
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