Dometic thermostat problem

I hope I have posted this in the right place. This has been an ongoing problem for over a year now.

This is on a 2016 winnebago destination 5th wheel.

The thermostat is a Dometic comfort control center 2 model 3314080.000

The remote sensor has always read erratic on the inside temp. It will show 55 degrees in 90 plus temps. The reason I have put up with it for so long is sometimes it reads right , but after we got in from this last trip it has read in the 55 degree range.

Now I will ask for opinions on my findings, I got a heating pad , turned it on low, put the remote sensor for the bedroom air under it, sensor them read in the 80 to 90 range, and air ran fine, remove sensor and it will drop to 55 degree range, and of course ac goes off.

In the boards opinion, is this just a bad sensor, all other functions work fine on the thermostat, and if so can a new wire with sensor be replaced, or just replace the whole thermostat?

Since it works ok at 80+, the wiring and the thermostat seem to be OK. And the sensor responds to direct heat, which suggests that it works too, at least in the 89-90 range.  The only issue seems to be the location where it is normally installed. Could there be a cold air draft there? Maybe the a/c blows right onto it and drives the reading low?

I had a similar problem once in a 5W with heating - the thermostat location was in the path of the heat outlet and it quickly warmed up, shutting the furnace off. I mounted a small shield to divert the air draft and it worked fine for years.

What does Dometic say?  Have you called them? I would start with a new sensor or if there are 2 sensors then switch them and see if the issue follows.

Gary RV_Wizard said:

Since it works ok at 80+, the wiring and the thermostat seem to be OK. And the sensor responds to direct heat, which suggests that it works too, at least in the 89-90 range.  The only issue seems to be the location where it is normally installed. Could there be a cold air draft there? Maybe the a/c blows right onto it and drives the reading low?

I had a similar problem once in a 5W with heating - the thermostat location was in the path of the heat outlet and it quickly warmed up, shutting the furnace off. I mounted a small shield to divert the air draft and it worked fine for years.

Click to expand...

Gary, the reading drops very quickly, when removed from pad, the remote will read 55 if no ac is running.Just got thru going out to trailer, looked at inside temp on bedroon remote ,said 45 degrees, it was at least 90 in that room. I did not have heating pad on.

keymastr said:

What does Dometic say?  Have you called them? I would start with a new sensor or if there are 2 sensors then switch them and see if the issue follows.

Click to expand...

I plan on calling dometic tomorrow,after the holiday. I hope to be able to just purchase a new separate remote sensor wire.

The strange thing is that the remote does respond when you apply heat. It's a pretty simple device, so if it works at all, it probably works correctly. And if the thermostat loses contact with the remote, it usually defaults to its local sensor instead. Presumably its not 45 near the thermostat itself, either. Maybe Dometic can clarify what happens in the CCC2 if the remote fails to read at all.

This is probably the remote sensor kit if you want to try another one .
http://www.dyersonline.com/dometic-ccc-and-ccc2-polar-white-20-remote-sensor-kit.html

Gary RV_Wizard said:

The strange thing is that the remote does respond when you apply heat. It's a pretty simple device, so if it works at all, it probably works correctly. And if the thermostat loses contact with the remote, it usually defaults to its local sensor instead. Presumably its not 45 near the thermostat itself, either. Maybe Dometic can clarify what happens in the CCC2 if the remote fails to read at all.

This is probably the remote sensor kit if you want to try another one .
http://www.dyersonline.com/dometic-ccc-and-ccc2-polar-white-20-remote-sensor-kit.html

Click to expand...

Thanks Gary, I talked with dometic, they think its the remote sensor, just ordered a new remote sensor kit from dyers when I saw your response in the email. I think this will work, at least I hope it will.

Well back to hunting a gremlin.

Got new remote sensor in the mail.

Went to install, but before I did , I read the inside temp readings on both front and back. They both read the same 87 degrees!

I went ahead and plugged in the remote sensor wire to the upper unit , did a reset on the thermostat, fired the bedroom unit up, in about 30 seconds it shut down, inside temp read 65 degrees, and the sensor end was covered up.

So, is the whole thermostat, control board bad?

Another question, My model # is 3314080.000, but I see 3314082.000 for sale in a bunch of sites, but I cannot find any info on whether or not they are interchangeable.

I will call dometic again monday, but my first call was not very productive. Old Texan conversing with young girl, language barrier.

Any thoughts on the matter would be appreciated. 

RWR said:

Well back to hunting a gremlin.

Got new remote sensor in the mail.

Went to install, but before I did , I read the inside temp readings on both front and back. They both read the same 87 degrees!

I went ahead and plugged in the remote sensor wire to the upper unit , did a reset on the thermostat, fired the bedroom unit up, in about 30 seconds it shut down, inside temp read 65 degrees, and the sensor end was covered up.

So, is the whole thermostat, control board bad?

Another question, My model # is 3314080.000, but I see 3314082.000 for sale in a bunch of sites, but I cannot find any info on whether or not they are interchangeable.

I will call dometic again monday, but my first call was not very productive. Old Texan conversing with young girl, language barrier.

Any thoughts on the matter would be appreciated.

Click to expand...

More info, I know this sounds crazy, but I will explain as best I can.

1.I decided to just unplug the sensor wire connection in the bedroom upper unit, thinking that would break the connection with the control
  board. Inside reading 87 degrees.
2.I cranked up the bedroom ac, ran it for 5 min ,no shutdown, inside temps read 87 whole time.

3. Shut down bedroom unit, cranked up living ac, worked fine, dropped 1 degree inside temp, did not run but a couple of minutes

4. so looks like that sensor wire did squat, or there's a wiring problem, at least I don't have to use a heating pad this way ;D

The solution was not a bad remote sensor after all. It seems that when the air conditioner was installed, the thermistor probe was stuck in the coils and the cold wet air was throwing the reading off. the unit was not properly taped of the keep the cold air and return air seperated. moved the thermistor to another location, so far seems to do the trick.

Hopes this helps someone down the road.