Need Help with Thermostat

[Carlosrod]

Hello Zoo.

Hope everyone is doing well and enjoying their camping season. We have been, but have a bit of a dilemma with our Dometic thermostat and it seems to be winning the battle. I've taking it to the dealer and been told that it's working fine, just off a few degrees and as a result, they will not replace.

I've decided to replace the thermostat on my own but have noticed that it’s a three-wire system, Red, White and Blue wires. Must've been a patriot who installed it. I’m guessing one will run the ac, the other the furnace and one will be a common wire. Anyway, I’m looking at a Honeywell type thermostat but was wondering if anyone has replaced theirs and can give me an idea of how to wire. Most thermostats I’ve seen (Home) have 4, 5 or 6 wires. Right now, I’m at a lost and can’t figure it out.

TIA for the help.

[oldmanAZ]

Check into installing a digital RV thermostat (Coleman Digital). I believe it is a wire-for-wire swap. Ours has been very accurate and is so much better than guessing at the settings with the analog thermostat.

OOPS EDIT: As norty1 pointed out, it may not work with a Dometic

[norty1]

Originally Posted by oldmanAZ

Check into installing a digital RV thermostat (Coleman Digital). I believe it is a wire-for-wire swap. Ours has been very accurate and is so much better than guessing at the settings with the analog thermostat.

Coleman may not work with a Dometic. Do some checking before purchase.

[o2silverado]

It is 12v +
12-
Comm wire.
It requires the thermostat and controller to be a matched pair. Wires nothing like a standard t-stat without a major rewire.

[CoCanCarv]

I use one of the most inexpensive digital t-stat's that honeywell makes and it is very good and I have stopped using my Fluke meter to tell me the temp. You can use the wire diagram that comes with the thermostat, you will use the three wire diagram and install the jumper on the common. I always have extra battery's because they always go out when you need it the most. Just read the instructions and you wont have a problem. It is just a thermostat a switch that opens and closes. Your old stat will most likely show what is hot and cold and common. They will give you stickers to put on the wires. I have a Jay Flight.

[Carlosrod]

Old Man,
Yes, I want to replace with a digital and one that displays ambient temperature. Not very impressed with these Dometic units.

[Carlosrod]

CoCan,

If you don't mind me asking, is your AC unit a Dometic unit and if it is, what model tstat are you using?
Thanks.

[CoCanCarv]

I use one of the most inexpensive t-stat's that honeywell makes and it is very good and I have stopped using my Fluke meter to tell me the temp. You can use the wire diagram that comes with the thermostat, you will use the three wire diagram and install the jumper on the common. I always have extra battery's because they always go out when you need it the most. Just read the instructions and you wont have a problem. It is just a thermostat a switch that opens and closes. Your old stat will most likely show what is hot and cold and common. They will give you stickers to put on the wires.
I have a Jay Flight.

Sorry about the double post. I use this one.
https://www.target.com/p/honeywell-1...E&gclsrc=aw.ds

[CoCanCarv]

It is a dometic 13,500

[Carlosrod]

Awesome. Thanks for the quick reply.

[o2silverado]

The new style domestic t-stat can not be replaced with a residential stat with out rewiring on the roof. The 3 wire rv configuration uses the communication wire to send a signal to the unit for all operations. A standard stat needs a wire for each operation. The roof top controller then interprets the signal and turns on the fan, a/c or furnace. The older units where easily replaced with a standard stat. The new 3 wire are not that simple.

[TWP723]

Originally Posted by o2silverado

The new style domestic t-stat can not be replaced with a residential stat with out rewiring on the roof. The 3 wire rv configuration uses the communication wire to send a signal to the unit for all operations. A standard stat needs a wire for each operation. The roof top controller then interprets the signal and turns on the fan, a/c or furnace. The older units where easily replaced with a standard stat. The new 3 wire are not that simple.

This. x2

[wanderlust]

A digital thermostat was my BEST upgrade:

https://www.youtube.com/watch?v=peQ0kxJ4tfg

[Carlosrod]

So, basically, I'm up the creek without a paddle and looks like I have to replace it with the same brand and model.

[Carlosrod]

Thanks for the video, Wanderlust. But that's not going to help. I'm trying to replace a digital unit that came with the camper, but Silverado makes a lot of sense.

[o2silverado]

Originally Posted by Carlosrod

So, basically, I'm up the creek without a paddle and looks like I have to replace it with the same brand and model.

At this point the only option is the non touch screen version. But it is essentially the same stat.