A/C actual temp reading

[SanAji]

The rear A/C is set at 80 degrees and the actual temp displayed is 75 degrees (it is not 75 degrees in the unit....98 outside), and the unit is not running. I turned it off, waited awhile before turning it back on, and when it came back on it appeared to be ok with it showing 85 and running like it should. Twelve hours later the same issue occurred again.

Does anyone know the cause and how to correct the issue?

We have had the new 3121RL for six weeks and really like it. Few minor issues, but this is the only potential major one.

Appreciate any advice, and I plan to make the dealership aware.

[MARK A]

I don't know who decides where to put the sensors,but both of ours are 1" from the wall one is behind the crown moulding. ��


Mark

[Baldicon]

If you are talking about the thermostat tucked in beside the "coffee bar", I had to set a small fan on the bar blowing air at the thermostat. It sits in a dead zone with little air flow around it. Mine tracks fairly close now.

[MARK A]

I was talking about the temp sensor in the ceiling. Mine is behind the crown moulding that covers the LED strip.


Mark

[Baldicon]

Oh ok. I didn't know there was such an animal. Looked it up and realize it is part of the dual zone system. I am of absolutely no help on this issue. And a lot of other issues too. Good luck.

[RMcNeal]

SanAji, yours sounds like a similar issue we have been having with the new Dometic dual zone touch thermostats and whisper quiet units. Haven't figured out what is going on with them, but your description is one of the symptoms. Sometimes, it will shut off and not turn back on regardless of how warm it gets, other times it will run and run regardless of how cold it gets. I tried removing the face plates, per Dometic and thought it had fixed the issue, but a few days later the problem started up again. Still not resolved. See this thread...https://www.montanaowners.com/forums...ad.php?t=81164.

[SanAji]

Thank you RMcNeal. I am not sure how I missed this thread, but it does appear that my unit has joined the A/C issue club. It is only six weeks old, we have not camped in it yet, been sitting in our driveway, and the issue just started. We have the In Command system, so no buttons to be damaged, and since we have not had it on the road...no wires/connections should have been disturbed.

Seems like an engineer should be able to resolve the issue.

[RMcNeal]

You're welcome. I don't have the In Command System. Are you saying you don't have thermostats, or just that the thermostats don't have any buttons?
The original theory was that the touch thermostats were the problem. According to Dometic, the touch sensor area has some sort of capacitive foam inside and pressing to hard on the "button" causes this foam to become compressed. When that happens, all sorts of weird things start happening. That's why we tried removing the face plates.
Our most recent theory has been that the freeze sensor on these blizzard systems is causing the issue. Brandon (BJacobs) is testing with the freeze sensor removed to see if that seems to fix it. Haven't heard anything in a while, but I'm hopeful for a solution.

[Elevguy]

Mine is similar, on the side of the pantry and above the hot water heater is problematic. Last trip out when I got home I left the ac on without hot water on it functioned well.

[BiggarView]

Not having any issues with our A/C. We have it set on 74 (using In Command system) and A/C has no trouble holding it there.

[SanAji]

Originally Posted by RMcNeal

You're welcome. I don't have the In Command System. Are you saying you don't have thermostats, or just that the thermostats don't have any buttons?
The original theory was that the touch thermostats were the problem. According to Dometic, the touch sensor area has some sort of capacitive foam inside and pressing to hard on the "button" causes this foam to become compressed. When that happens, all sorts of weird things start happening. That's why we tried removing the face plates.
Our most recent theory has been that the freeze sensor on these blizzard systems is causing the issue. Brandon (BJacobs) is testing with the freeze sensor removed to see if that seems to fix it. Haven't heard anything in a while, but I'm hopeful for a solution.

The In Command System has a “touch screen” rather than the buttons on the traditional thermostat.

I checked on the system this morning, and again I found that it displayed an actual temperature of 75 and my setting of 80 was still correct (it was not running because of it being told that the temperature was much lower than the 80. . It was not 75 in the Monty. For some reason it keeps going to this 75. It appears that the sensor is bad....not sure. The sensor is in a location that can not be impacted by any equipment or outside wall.

[Bob and Jeannette]

I have in command in my 3813 which has a RL configuration. The front gets ice cold quickly because of the smaller cubic feet than the rear but they both work ok. I recommend pointing all 4 vents towards the island and not to use the sink covers or else the bottom of the sinks will condensate quite a bit of water. One other thing with in Command is that the sensor is across from the door window which is a heat source. I covered mine with sunscreen material that I bought for this purpose at Camping World and it put my sensor right. I bought an indoor temperature and humidity display at Walmart that is quite nice for $12.

[SanAji]

Originally Posted by Bob and Jeannette

I have in command in my 3813 which has a RL configuration. The front gets ice cold quickly because of the smaller cubic feet than the rear but they both work ok. I recommend pointing all 4 vents towards the island and not to use the sink covers or else the bottom of the sinks will condensate quite a bit of water. One other thing with in Command is that the sensor is across from the door window which is a heat source. I covered mine with sunscreen material that I bought for this purpose at Camping World and it put my sensor right. I bought an indoor temperature and humidity display at Walmart that is quite nice for $12.

Thank you for the response. Rather than our sensor showing a higher temperature, it is displaying a lower temperature than the actual. I have to set the thermostat lower than what is displayed for it to come on. Frustrating! I hope to get it in the dealership soon....hope they can repair it.

[Bob and Jeannette]

Originally Posted by SanAji

The In Command System has a “touch screen” rather than the buttons on the traditional thermostat.

I checked on the system this morning, and again I found that it displayed an actual temperature of 75 and my setting of 80 was still correct (it was not running because of it being told that the temperature was much lower than the 80. . It was not 75 in the Monty. For some reason it keeps going to this 75. It appears that the sensor is bad....not sure. The sensor is in a location that can not be impacted by any equipment or outside wall.

Set for 80 it should turn the a/c unit off at 79 of course. Can’t wait to hear the conclusion.

[muster]

This may not be the same issue, but here is our experience.
We picked up our 2020 3855BR Legacy in early June (we ordered it and it was build around March 1st). Fortunately we took the RV dealer up on spending two free nights in their campground, especially since we are new at RVing and have never owned a RV.
We hooked up to 50A power and proceeded to try to get the AC to work since it was a hot day. The InCommand monitor showed our inside temperature as -- (yes dash dash). We were only a quarter mile from the service department, so we had a service tech come over. First off, the tech said we have Coleman AC units rather then Dometic. He said the factory had just switched to using Coleman and this was his first experience with Coleman. He could not find anything wrong with the AC units and finally did what he called a hard reset by cutting all power to the Monty, including the battery. When he turned the power back on everything worked and has been working fine since.