Upgrading thermostats

[mikerstevens93]

Our 2019 keystone Montana 3701LK has 2 thermostats and 2 AC units. The one for the living room and kitchen area went out. It’s a black Dometic 3 wire capacitive touch thermostat, there was a 4th unused wire also with the 3 wires. We bought a Honeywell RTH9585WF thermostat, but we’ve never had to replace a thermostat before so we need a little guidance on how to wire this exactly.

The picture shows the old thermostat on the right with the available wires in the middle and the new wire hook up thing on the left. The red wire is the extra unused wire, I checked the other thermostat and the wire bundle for the optional third AC/thermostat and they also have the additional wire.

[sourdough]

Originally Posted by mikerstevens93

Our 2019 keystone Montana 3701LK has 2 thermostats and 2 AC units. The one for the living room and kitchen area went out. It’s a black Dometic 3 wire capacitive touch thermostat, there was a 4th unused wire also with the 3 wires. We bought a Honeywell RTH9585WF thermostat, but we’ve never had to replace a thermostat before so we need a little guidance on how to wire this exactly.

The picture shows the old thermostat on the right with the available wires in the middle and the new wire hook up thing on the left. The red wire is the extra unused wire, I checked the other thermostat and the wire bundle for the optional third AC/thermostat and they also have the additional wire.

As far as I know the only replacement for the Dometic CT thermostat is made by MicroAir at a cost of about $250. Prior to its recent introduction Dometic said there were no other thermostats on the market that would communicate to the control unit in the AC. If everything I've read and been told by Dometic is correct you can't use that Honeywell to replace the Dometic.

[Mikelff]

Originally Posted by mikerstevens93

Our 2019 keystone Montana 3701LK has 2 thermostats and 2 AC units. The one for the living room and kitchen area went out. It’s a black Dometic 3 wire capacitive touch thermostat, there was a 4th unused wire also with the 3 wires. We bought a Honeywell RTH9585WF thermostat, but we’ve never had to replace a thermostat before so we need a little guidance on how to wire this exactly.

The picture shows the old thermostat on the right with the available wires in the middle and the new wire hook up thing on the left. The red wire is the extra unused wire, I checked the other thermostat and the wire bundle for the optional third AC/thermostat and they also have the additional wire.

Sourdough is correct. Return that Honeywell, as it will not work. Call Dometic and raise hell about it. They will likely send you a new one. They are still having problems with that thermostat. Most are junk, but sometimes you get one that works. Otherwise the $230 replacement is your only option.

[Jamesb]

I didn’t have to say much to get replacements. Just said it don’t work right, and I like it. They shipped two of them to us. They know they have a problem with them, and don’t put up no fight. Good luck.

[sourdough]

I would add that like Jamesb, I contacted them and they sent replacement thermostats explaining the ct units had problems. At the time she just said it was a "bad batch" but that batch has continued for at least 2 years.

[RMcNeal]

Add ours to sourdough as well. We have replaced the face plates, the whole thermostats, control boards, freeze sensors, etc. Still have the same problems. AC will run fine for a while, then shut off never to return without resetting the thermostat.
I am skeptical that the thermostat is the problem we are experiencing, but I do know the CT thermostats are a problem for anyone who pushes the buttons like they are buttons. Apparently, the foam under the button area is what is used for the CT function. It gets compressed when pushed too hard and causes the thermostat to go wonky. According to Dometic, you are only supposed to lightly touch it like a cell phone screen, not press it like a button.