Dometic 3313192.xxx thermostat off 20 degrees

[BillScott]

Had this 2015 HR Salem Hemisphere RV for about a month. The first trip the thermostat was working fine, except I had to set the fan to auto. But the last day of the trip, with the temp set at 70 degrees the furnace wouldn't come on. Thinking I was out of propane, I switched the bottles and still the furnace would not come one. When I set the thermostat to 90 degrees, it finally came on and heated the trailer up to 69 degrees and then shut down. Through trial an error, I discovered that by setting it to 80 degrees it would turn off at 60 degrees. Dometic said, take it in for service. I am going to try the reset function first. But before I do, I though I would pass this question along to the forum and see if anyone has had a similar experience.

[Flybob]

Try this .
A system initialization will need to be performed by the installer after
the system is installed.
• Make sure the Single Zone LCD thermostat is in the Off condition.
See page 4, “Quick Reference To Control Buttons”.
• Press the “+” button and, while holding it, also press and hold
the On/Off Mode button for three seconds. LCD will show
― ― . Press the On/Off Mode button again to turn system off.
This completes the initialization

[BillScott]

Tried that flybob, It appears to be only 10 degrees off now. Looks like resetting to factory specs doesn't do it.

[mjones12]

Good info. Any reason not to do this if the T-stat just seems to be 5 or 6 degrees off?

[BillScott]

Last night, I set the thermostat to 60 degrees. This morning the temp outside is 37, and it's 42 degrees inside the coach. I turned the thermostat off, then back on, and the furnace started running. My guess is it will shut down in a few minutes. The thermostat is selling n Amazon for $23. It's under warranty of course, but I am wondering if I buy the new thermostat and replace it, if it will solve the problem. Or based on the symptoms, could it possibly be the furnace that's a fault?

[Bama Rambler]

It's probably the T-stat, but with these electronic units it could be the control board inside the A/C unit.

If it's not a huge pain, I'd suggest taking it to the dealer.

A new head unit and control kit is about $90.

[carluv]

FlyBob, my T stat is about 10-12 degrees off. The page 4 you mention, is that in a Dometic book somewhere?

[BillScott]

**UPDATE**
After a 250 mile pull, the furnace works again. I think I need to search for a loose wire or a cold solder joint,

[Flybob]

Originally Posted by carluv

FlyBob, my T stat is about 10-12 degrees off. The page 4 you mention, is that in a Dometic book somewhere?

Yes see attached