Dometic Thermosat

BGraydon

Member
Hello,
New member and first post and first time RV owner . Bought a 2019 Pioneer RD210 in April. The furnace worked during the 30 minute training we received. Took the RV to the north GA mountains last week and the furnace did not work. The manual Dometic thermostat would not start the furnace the first night. The second day it did work and worked the rest of the time. So now even though it still works (and still under warranty) I'm taking it back to Camping World for a check up as to why it didn't come on the first time. I also bought a digital thermostat and tried installing (only two wires red and white) with no success. Wondering if anyone else had this happen? Should I expect good results when I take it in for service or will I be disappointed? Will they install the digital version for me?

Thanks,
Blair Graydon
Newnan, GA
 

danemayer

Well-known member
Hi BGraydon,

Welcome to the Heartland Owners Forum.

Starting with the last, it's unlikely the dealer would try to modify the equipment and there's no way they would be reimbursed under warranty. Also, Dometic thermostats in general are not interchangeable with hardware store thermostats. But who knows - yours might be the exception.

Also, unfortunately, techs are not very good at solving intermittent problems. That's understandable because if you can't see it fail, you're just guessing about possible causes. And again, it's hard to get a manufacturer to reimburse for "no trouble found" service calls. So they may not spend a lot of time trying.

But if you can describe the failure more thoroughly, and what you may have done to get it working, someone here may be able to help. For example, with Suburban furnaces, when the thermostat calls for heat, the first thing that happens is usually a click (relay operating) noise overhead immediately followed by the furnace blower running for 25 seconds, followed by an ignition attempt. So - did you hear a click? Did the blower run?

After you found it not working, did you do anything like check the propane flow? Close/reopen the propane tanks? Were you hooked up to shore power at the time, or running on battery? A more complete description of the entire situation and what happened would be helpful.
 

BGraydon

Member
Thanks Dan and Ann for the reply.
The upgraded digital thermostat is a Dometic. I got it at a Camping World and the worker said it would work for my camper. It takes 3 wires including a ground. The current TS takes two.

The conditions last week were as follows: shore power used and propane lines on (stove and hot water heater were working fine).
After several attempts the first night we gave up. The next morning my wife hit it with her fist and flipped the switch and it came on. No click is noticeable but immediately the blower came on and then a few seconds later the furnace started. After that it has been working fine except when I tried to install the digital TS after we got home. I could not get it working so I put the original back on.
It almost seems like the road travel made the wire loose but the problem is definitely that the TS is not telling the blower/furnace to turn on IMO.

Thanks for your help.

Blair Graydon
 

danemayer

Well-known member
The symptoms where there was no blower, but started working after hitting the thermostat suggests either a loose connection at the thermostat, or a defect in the thermostat.

If it's an analog thermostat, which might have a lever that sets the temperature by moving a mercury switch that's under the covers, the digital Dometic thermostat may not be compatible. But if the analog thermostat uses 2 wires for the furnace operation and carries 12V DC on those wires, you could probably replace it with a digital residential thermostat from the hardware store. The open question is how the Air Conditioner is wired to the thermostat.
 

BGraydon

Member
Are you saying the wire to the thermostat comes just from the battery? If so that makes things easier right?

I guess it is an analog thermostat. The temp lever trips a spring. Not sure about this.

The A/C is on the roof and totally separate from the furnace.

I decided against taking the camper for service. I would be more than happy to find another thermostat at a hardware store that only take two wires. But until it stops working it is impossible to troubleshoot.

Blair
 

danemayer

Well-known member
Here's a link that may be helpful. This wiring diagram is down near the bottom of the page.

RV-Thermostat-Wiring-Diagram-with-Conversion-for-Home-Thermostat-1024x576.jpeg
 
You can go to tools on the top of page then heating and cooling someone posted a guide on using a res thermostat. Many guides and tips by using the tools section of this web site. I used a $20.00 Digital Residental. thermostat and added a toggle switch for the fan speeds. It works both air and heat.
 

amscholer

Member
We have a 2017 3760EL Bighorn fifth wheel our dometic thermostat all of a sudden has jumbled txt for the furnace mode. Furnace works fine just. Just txt looks crazy. It was fine yesterday and our bedroom thermostat reads correctly. Not sure if this is a sign the display is starting to go bad or not.
Would appreciate any suggestions or advice.
Thanks!
Annette & Steve
 
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