Dometic Theromstat

[BobRairigh]

UGH! My Dometic controls are the worse user interface for touching. In my 2018 3811MS if you breathe on the controls they turn on. If you touch them to change anything they won't and then will go crazy. The AC and furnance will sometime just run up to 90 just randomly. I swapped the bedroom control interface with the main room and it has not fixed it.

Any suggestions?

I would like to replace the interface with a bluetooth controlled module, I have not googled anything good.

Can I replace the wall units with something better?

Anyone have the same issue?

Thanks,
Bob

[432bartman]

Curious as to this as well.

[sourdough]

What thermostat do you have? Is it the "capacitive touch" unit? If so they are just bad.

Dometic told me back in 18? they had some bad batches of thermostats. I replaced mine 4 times and carried a spare. They said there was nothing else compatible. One of us could walk by it and it would go wacko. Replaced faceplates, cut/modified the foam underneath, used my fingers on the metal probes...crazy. Unfortunately the new HC has them as well. The main one gets on a tangent and I have to go reset it every now and again...day or night, but at least it doesn't decide it needs to be set at 90 when it's 100 outside. I have seen that MicroAir??? or someone like that now makes a compatible thermostat. From what I remember it was kind of spendy but I kind of like things to work.

[BobRairigh]

That rocks! I love this forum. Micro-Air is awesome. I have their Easy Start...looks like I am ordering the Easy Touch replacement!

https://www.microair.net/products/ea...56#CompatChart

[Daryles]

I read an article where a guy wired in a Honeywell thermostat. However IT, turned on/off the Dometic thermostat.

[RMcNeal]

Bob, I have had issues with our Dometic A/C as well. Dometic originally thought it was the CT Thermostats and sent me new face plates. It seems that the capacitive touch foam under each button can become smashed when you push too hard, (LIKE WHEN FRUSTRATED BECAUSE THE ?&*))#@(* THING DOESN'T WORK), and then you'll get the crazy results you are seeing. Just pull off the face plates. You can still work the thermostat by touching the metal blade beneath each button. Call Dometic and they will send you new ones. They already know it's an issue. BTW, according to Dometic, no other thermostat can work with these A/C units and the control boards that they use to communicate with each other. Otherwise, I would have replaced them already.

[ChuckS]

most house style thermostats require 24 volts.. even if you supplied a transformer to power or bought one that would work off battery power only the issue will be the CANBUS that is needed to communicate to the AC control module

[432bartman]

So it's the faceplates and components that are causing many of these units to not function in the auto setting and only work on hi or low?

[RMcNeal]

No. Initially the face plates were the theory, but after running with them removed for several days, the problems with shutting off and not turning back on returned.
The face plates are the cause of the display going "wonky" and changing itself seemingly at random. It appears that the compressed foam simulates a finger touch so the tstat will respond even though no one is touching it. It also seems to exhibit this behavior when being brushed by your shirt sleeve or clothing. Even the lightest of touch will cause it to respond when it shouldn't.
The problem we are having with the unit getting down to temp, then shutting off and never turning back on has not been resolved AFAIK. Still can't seem to find that gremlin. Prevailing theory is that it's either the freeze sensor or control boards between the two blizzard units.

[Chris and Den]

Wow thankful we found this group! We have read a lot of the same issues we have others have been having... our dealers famous line is “ oh never heard of anyone else having that issue”!

We have a 2018 3790RD Montana, and has had a lot Of issues.
The newest is the Dometic thermostat, we have two, one in the bedroom and the other in the main area. Things had been working fine up until a month ago. ( well don’t know if the heat pump works, never have used it)
However, like so many have mentioned the Dometic thermostat does what it wants. First it was the main unit that started to act up, and no matter what you tried it wouldn’t turn the ac on. We pulled off the faceplate and swapped it with the bedroom one and it didn’t make much difference.
So we have left the faceplate off the main one and just touch the little sensors, so for the most part the main unit will work, but every so often it needs to be turned right off and give it a few minutes and it will function again.
Our newest issue is with the unit in the bedroom, set it to auto, ac, it turned on fine, it then went on and off 4-5 times in a row, then worked fine until at some point in the night it didn’t go back on and when we woke in the morning it was warm in the bedroom and we tried lowering the temperature ( arrow down) all the way to 64 and the ac wouldn’t come on.
Any suggestions?
Like mentioned our dealership tells us they’ve never heard of that issue!

[Kyle and Lisa]

We have the same issue, Dometic sent us new faceplates and still had the same issue. I leave the faceplates off and have not had any issues in 3 years.

[RMcNeal]

Chris and Den, what you describe is exactly what we have been dealing with since we got our unit. I have a 2019 3791RD, same as yours only the Residential fridge. At some point, the unit shuts off usually because it has reached the set point temperature, then it will not turn back on until it is reset no matter what you do. I have to shut off the unit at the tstat, wait for several minutes, then turn it back on and it will run fine for a while and shut off again. No rhyme or reason as to how long it will run. Could be 2 hours, could be 2 days, but at some point it will shut off and not turn back on until reset no matter how hot it gets inside. Oddly, with ours, the unit in the living room seems to shut off like this much more than the bedroom. They both eventually shut down, but I seem to have to reset the living room unit more often than the bedroom. It's gotten to where I just reset it every morning when I get up even if it's running at the time just to try and prevent it from shutting down. I have 2 english bulldogs and they can't handle heat like most dogs. Very disappointed in Dometic. They should be able to figure this out by now.
Don't bother with the dealer. Even if they are willing to help, most won't pay someone to sit and wait for the problem to happen, especially when it could take days.
Another thing we've had it do is start "short cycling". Essentially, it will run for 60 seconds, shut off for about 3 seconds, then turn on for another 60 seconds. Sometimes the fan is high, sometimes low. It appears very random.
Brandon Jacobs have posted You Tube videos displaying this to show Dometic what is going on. See our thread at https://www.montanaowners.com/forums...ad.php?t=81164.

[RMcNeal]

That's great. I had face plates off for about 5 days, but the problem returned even with face plates off.

[Kyle and Lisa]

Sometimes I have to force the fan on high and then switch it back to auto if I think the a/c should be running and it's not.

[RMcNeal]

I've tried putting fan on High and low. All I get is the fan keeps running but the compressor shuts off. No cooling. I haven't tried doing that when it is off, but I can't imagine it would be any different. Our rig is in the shop getting the awning fixed so I can't test that right now. It started pulling off the outside wall. I've only opened it 2 or 3 times and never in any wind, but that's another story.

[Skw774]

They sent me new ones when i called

[Mikelff]

As some may have read, Keystone is now sending their units out with Coleman AC units. That should tell you something. I’m sure Keystone got sick of all the warrenty repairs and not being able to fix it. Cost them a fortune. I’m sure the dealers are bending their ear about it. My dealer told me they replace those thermostats probably 3 to 4 a week. I bet you don’t see any Dometic AC units on the new RV’s for a while. In the meantime, our issues continue. Perhaps the loss of this business will entice Dometic to get these issues resolved. Time will tell. Hope you all get it resolved. So frustrating!

[RMcNeal]

Has anyone tried the Micro Air thermostats? I'm kinda reluctant to spend $250 on a tstat just to see if it fixes the issue. If I know it does, then that would be fine. Just don't want to waste money and still not have a fix.

[sourdough]

Originally Posted by RMcNeal

Has anyone tried the Micro Air thermostats? I'm kinda reluctant to spend $250 on a tstat just to see if it fixes the issue. If I know it does, then that would be fine. Just don't want to waste money and still not have a fix.

I'm in the same boat. I'm thinking I want them but that's a chunk of change for a thermostat....especially if it isn't any better. Hopefully someone has taken the plunge and can shed a little light.

[RMcNeal]

Exactly my thought. I don't want to spend $500 bucks for new Tstats just to have the same problems I have now. I don't care about using my phone to control it. I usually set and forget, except I can't now because it doesn't work like it should.