Help with 2 Zone AC

[vettman1]

I have a 2018 Alpine 3900RE and the front sensor in the coach (Zone 2) doesn't seem to be reading correctly. My wife said this past weekend that it seems like the temperature readings (when you click inside temp) and switched. Is it possible that it never got wired correctly? I have two remote sensors in the RV, one in the kitchen and one in the bedroom. Do they hook into the AC units or in the back of the thermostat? How do you take the thermostat off the wall?

Any advice/recommendations are greatly appreciated!

[chuckster57]

A picture of your thermostat would help. Remote thermistors are connected to the thermostat as far as I know.

[vettman1]

Originally Posted by chuckster57

A picture of your thermostat would help. Remote thermistors are connected to the thermostat as far as I know.

It looks like this one. https://www.dometic.com/en-us/us/pro...center-_-52919

[ChuckS]

To read each zone temp with the Dometic CCC2 thermostat ... that’s what’s in your Alpine make sure you have Zone 2 selected then press inside temp

Now switch to Zone 1 and check it’s temp ...

There is nothing serviceable inside that thermostat but it simple lifts up and out off its mount. There is a telephone cable connected to back of it that links CCC2 up to roof Zone 1 and Zone 2 AC units as well as furnace.

You can try a reset on CCC2 and see if that clears up the issue of temp variance.

[ChuckS]

Also in that model the Zone 2 AC is front unit for bedroom and Zone 1 is for LR area.

[ChuckS]

Another items to check is remove plastic cover over remote sensor for zone you believe is having issues and verify it’s mounted outside the wall like in this pic.

Some Alpine owners have had issues and the sensor was mounted inside the wall against an aluminum stud. This will cause big error in ambient temp readings.

I’d also run that AC unit and with remote sensor cover removed feel if there is cold air blowing thru ... if so then seal off the hole so that cold air doesn’t blow out onto sensor.

[ChuckS]

If you aren’t sure how to do a reset on CCC2 this will help you... read page 19 of link

https://www.dometic.com/assets/47/55...5.pdf?att=true

[bobbecky]

On a Dometic CCC2 thermostat system, when there is a remote sensor, it is wired to the CCC2 control box mounted below the A/C unit. On our rig, the zone 1 unit is the rear A/C unit and the thermostat is the sensor for that unit. The front A/C has a remote sensor on the ceiling, and that is wired to the control box. You can access the control box by removing the plastic grill from below the A/C.

[vettman1]

Originally Posted by ChuckS

Another items to check is remove plastic cover over remote sensor for zone you believe is having issues and verify it’s mounted outside the wall like in this pic.

Some Alpine owners have had issues and the sensor was mounted inside the wall against an aluminum stud. This will cause big error in ambient temp readings.

I’d also run that AC unit and with remote sensor cover removed feel if there is cold air blowing thru ... if so then seal off the hole so that cold air doesn’t blow out onto sensor.

My sensor is barely past the plastic tab that is holding it. Maybe I'll take a look at mounting it like yours to see if that makes a difference.

Anyone got installation instructions on these sensors?

[vettman1]

Originally Posted by bobbecky

On a Dometic CCC2 thermostat system, when there is a remote sensor, it is wired to the CCC2 control box mounted below the A/C unit. On our rig, the zone 1 unit is the rear A/C unit and the thermostat is the sensor for that unit. The front A/C has a remote sensor on the ceiling, and that is wired to the control box. You can access the control box by removing the plastic grill from below the A/C.

Both of my AC units are "whisper" air so they dump cold air into a circular track in the ceiling. So does the sensor hook directly into the AC unit or is there another box it is plugged into?

[chuckster57]

I learned something new today. If the remote thermistor is wired to the control box, then it should be accessible from the roof on the “whisper quiet” system.

Remove the AC plastic cover and it should be in the return ductwork after you remove the metal plate at the front of the unit.

[ChuckS]

Both Air conditioner units have their own separate control modules mounted under the covers on the roof... each unit has its own separate remote sensor...

[ChuckS]

This is an overview of the CCC2 system... the file covers both In Command and CCC2 versions of HVAC control.