thermostat has a mind of its own

[Columbo 5]

We have put this issue on the back burner for a while but now it is just getting frustrating. We have a 2017 Columbus 370 BH. We have the thermostat set to off as to not use electricity right now because its in the 60s and 70s outside. We left the camper for a few days and when and saw my mother in law. So we set the AC to 80 degrees and then turned off the system. When we got back at 9 last night it was 64 inside the camper and the AC was on and running and it was set to 77. So I turned it off again this morning it was 60 inside and the AC decided to come on again. Is there anyway to reset it? Or is there a different thermostat I can replace it with? Thank you for your help

[DavidBo]

Does it have a mechanical or digital thermostat? The old analog units are pretty much garbage, and upgrading to digital is usually pretty easy. A lot of folks adapt residential thermostats because they are cheaper and can have more features, but I stuck with the original brand because it was a simple wire for wire replacement.
I suppose something else could be the problem, but a bad thermostat would be a good first guess.

[Bama Rambler]

It would help a lot to know which thermostat you have. Without knowing that we don't know how to reset it or even if you can.

[Columbo 5]

The thermostat that we have is a RV Comfort ZC. It is taller that it is wide has a digital screen and 5 buttons below the screen to control the temperatures.

[DavidBo]

This might help:

https://experiencelife.lamesarv.com/...ostat-control/

[Larry-NC]

Originally Posted by DavidBo

Does it have a mechanical or digital thermostat? The old analog units are pretty much garbage, and upgrading to digital is usually pretty easy. A lot of folks adapt residential thermostats because they are cheaper and can have more features, but I stuck with the original brand because it was a simple wire for wire replacement.
I suppose something else could be the problem, but a bad thermostat would be a good first guess.

The mechanical thermostats don't go crazy like the OP's digital thermostat. A low battery or power glitch doesn't cause them to loose their settings and cool the trailer to 64 degrees. No one has ever had these problems with an analog thermostat.

Now, you tell me, which one is garbage. I'm sticking with the simple, trouble-free analog units.

[DavidBo]

Originally Posted by Larry-NC

Now, you tell me, which one is garbage. I'm sticking with the simple, trouble-free analog units.

I had two trailers, both with analog thermostats. When using the A/C, neither one could come close to maintaining an even temperature. At night the interior would get quite warm, then the A/C would finally kick on and run until it got really cold. I did a little research on this very forum and found that was pretty typical. I switched over to the digital equivalent and now the temp stays within a few degrees.
I was concerned that the new thermostat would lose its setting if the shore power was to cut off briefly, bad news if you leave pets inside on a hot day, but since mine is made for RVs the battery keeps it online. I understand some retrofitted household thermostats won't always do that.
To each his own, I just find the digital style to be a lot more comfortable, especially since I often camp way down it the tropics.

[Larry-NC]

Originally Posted by DavidBo

I had two trailers, both with analog thermostats. When using the A/C, neither one could come close to maintaining an even temperature. At night the interior would get quite warm, then the A/C would finally kick on and run until it got really cold. I did a little research on this very forum and found that was pretty typical. I switched over to the digital equivalent and now the temp stays within a few degrees.
I was concerned that the new thermostat would lose its setting if the shore power was to cut off briefly, bad news if you leave pets inside on a hot day, but since mine is made for RVs the battery keeps it online. I understand some retrofitted household thermostats won't always do that.
To each his own, I just find the digital style to be a lot more comfortable, especially since I often camp way down it the tropics.

The gap between start temperature and stop temperature is called, technically, hysteresis. I agree that a wide hysteresis gap is annoying. A too-narrow gap is also annoying. You wouldn't want the furnace or AC to repeatedly run for 30 seconds and stop for 30 seconds, either--in fact it's very hard on the AC compressor (called starting against head pressure).

What is ignored here is that hysteresis is adjustable on analog thermostats and not on digital thermostats. In the trade, the adjuster is called the "anticipator." It's a small rotary rheostat (potentiometer) on the back of the thermostat--you must remove the thermostat base from the wall to adjust it. Typically they are set to around 0.8. Very small adjustments should be made--it doesn't take much to make a big difference.

The anticipator is easy to burn out. If you don't know what you are doing and put 12v across it, you will destroy it. You could possibly damage it by measuring it with an ohmmeter on too high a scale. (Ohmmeters force current through the unknown resistance and measure the voltage drop.) If the anticipator is destroyed, you will get short on/off cycles.

[leblancdave]

Sounds like what everyone is saying is that a digital thermostat should not have this problem. But, I do. Since the previous post says only analog are adjustable, does that mean I should replace mine?

[Artspe]

Most likely, you have a bad thermostat. I had the same problem until changing my thermostat (for same model).

[TheWolfPaq82]

"What is ignored here is that hysteresis is adjustable on analog thermostats and not on digital thermostats. In the trade, the adjuster is called the "anticipator." It's a small rotary rheostat (potentiometer) on the back of the thermostat--you must remove the thermostat base from the wall to adjust it. Typically they are set to around 0.8. Very small adjustments should be made--it doesn't take much to make a big difference."

Interesting. Both my digital in my house and my TT, the hysteresis...or "temp swing" as a layman might call it are both adjustable. I go into the "Settings" and I believe I can set it between 1 and 3 or 1 and 5...been so long...years in fact, that i'm not sure on the total swing.

[Bama Rambler]

Almost every digital thermostat I've seen has an adjustable deadband. Some don't call it that, but they have it. Even the Dometic one in our RV has a deadband that can be changed.

[ependydad]

Anyway, this bickering over analog vs. digital thermostats is doing nothing to help the OP.

Columbo 5, can you post a picture of your thermostat? The Dometic capacitive touch ones are known to have a mind of their own. Replacing them is about your only recourse. If you can find one with the hard buttons, they're generally much better than this stupid capacitive touch design.

Here's a stock picture of the capacitive touch ones:

[RobnCari]

Originally Posted by ependydad

Anyway, this bickering over analog vs. digital thermostats is doing nothing to help the OP.

Columbo 5, can you post a picture of your thermostat? The Dometic capacitive touch ones are known to have a mind of their own. Replacing them is about your only recourse. If you can find one with the hard buttons, they're generally much better than this stupid capacitive touch design.

Here's a stock picture of the capacitive touch ones:

That is the same thermostat we have in our R-Pod 179. It occasionally gets "a mind of its own". I found pulling the face off and letting it reset "cures" the problem albeit temporary. I would think pulling the fuse would have the same results.

[DavidBo]

From what the OP described in post #4, I imagine it looks more like this one: