Thermostat Issue

[Kalidas]

Hello Everyone,
So the Dometic Control Unit seems to be working fine. Except that the internal temperature reading is 0C or 32F.
So..the furnace will not stop running.
Tried resetting it by removing it from the wall, but still has same reading.
Do I need to replace the unit?
Thanks

[OTRA15]

Have you done the hard reboot procedure described in your Dometic instruction manual, to reset the thermostat to its factory settings? This often fixes things IMO.

First I would turn off and on, all circuit breakers which relate to the Dometic unit, both 120-volt and 12-volt for its control circuitry. You should also disconnect from shore power, and then reconnect, in order to let the unit's brain reset internally. Your Airstream owner's manual will help you locate the two circuit breaker panels.

After the above steps, it will be easier for someone with more Dometic knowledge than me to advise of any further possible problems. Replacing the stat is one possibility for sure.

"Dometic stat hard reboot" --

https://www.google.com/search?q=dome...=airforums.com

Good luck!

Peter

PS -- Do you have a surge protector inline for your shore power? Had any electrical storms recently? Do all the other electrical functions work OK, both 12 and 120-volt? What is your battery voltage on the control panel?

[AirMiles]

In August, the Dometic thermostat in my 2017 FC25 did the same thing, reading 32 degrees inside when the actual temperature was about 100 degrees. Taking it off the wall and disconnecting it was easy, but did not fix the problem. So after one hot and sleepless Florida summer night, I towed my Airstream to Camping World to buy a replacement thermostat for about $100. Towing the Airstream must have jostled the thermostat so it was working again when I went to replace it. I decided to leave the original thermostat installed and keep the new one for a backup. I have since used my A/C for more than 30 nights without another thermostat problem. Therefore, all one needs to do to fix the thermostat is to buy its replacement! LOL

[OTRA15]

Did you try any of the reboot/reset suggestions in Post #2? Coincidentally, by removing the stat and re-installing it, you may have forced it to reboot on its own. Doubt if the jostling of the road trip had much to do with it IMO.

Glad it worked again, and that you have a spare!

[AirMiles]

OTRA, no I was was unaware about rebooting the thermostat until reading your post. Maybe having the Airstream disconnected from shore power while traveling forced the reboot?

All I know is that the 32 degree issue happened a couple of times the day before buying the replacement and never since. I was able to get the thermostat to work for a short time by disconnecting and reconnecting it, but when it failed the second time I could not get it to work again. Then after traveling about a hundred miles it started working again and has not had another issue.

I just thought I'd share my experience with this issue with the OP. I will try the reboot if this issue ever happens again.

[OTRA15]

Wondering if you have sorted this out?

Thanks,

Peter

Originally Posted by Kalidas

Hello Everyone,
So the Dometic Control Unit seems to be working fine. Except that the internal temperature reading is 0C or 32F.
So..the furnace will not stop running.
Tried resetting it by removing it from the wall, but still has same reading.
Do I need to replace the unit?
Thanks