Replacement of Dometic AC

[dewdev]

 

I am researching replacing my Dometic AC with the new Truma Aventi ECO AC unit  during the Truma free install offer

The Truma AC unit is rated at 13, 5000 BTU/hr. It requires at a minimum CG power connection of 20 amps. Condensate is handled by an internal drain tube using their interior drain kit.

I got a call from the Truma installer as I had a few questions the sales person could not answer.  I was told that the furnace would work with the Dometic thermostat if the controller which is probably located above the interior AC air distribution cover. I remember seeing on this forum that people were having to install a different furnace controller after changing out the Dometic AC.

QUESTION: For those that removed your Dometic AC unit, was the thermostat controller located up in the AC unit and could not be reinstalled thereby  requiring a new thermostat for the heater?

[bhncb]

44 minutes ago, dewdev said:

was the thermostat controller located up in the AC unit and could not be reinstalled thereby  requiring a new thermostat for the heater?

Yes and yes but consider that:

If it's an issue, the resale value of the Dometic PII will be greatly reduced without the CT thermostat and controller. The Dometic A/C model # includes these components so you'd be attempting to sell an incomplete unit.

The Dometic CT thermostat is four mode but will only be able to support one off these, the furnace. Using it this way may be confusing for some.

The CT thermostat is finicky at best to use, especially in colder months when fingertips are likely to be dry. A replacement digital single-mode thermostat, like a Honeywell or Emerson, will be easier to use and more reliable.

From a labor cost prospective, it shouldn't be much more involved to install a replacement thermostat than to remove and reinstall the Dometic controller.

 

I understand that Truma techs will want to take the path of least resistance so as to not exceed the $250 installation coupon, but don't believe this approach will be in your best interest.

[dewdev]

Thanks bhncb:

If the Dometic thermostat is replaced with the Emerson non-programable thermostat which existing wires are connected to the Emerson?

[bhncb]

17 hours ago, dewdev said:

Thanks bhncb:

If the Dometic thermostat is replaced with the Emerson non-programable thermostat which existing wires are connected to the Emerson?

Sorry. i missed this one.

Based on your hull number I’m guessing you’ll only have three wires in the existing thermostat cable. Probably red, yellow, and green. Since the thermostat must be battery powered, pick any two of them to represent voltage from and heat call to the furnace.

Looking at the furnace wiring diagram, the two wire colors chosen will logically be representing the blue/white wire going out to the thermostat R terminal and the solid blue wire coming in from the W terminal, respectively. However, since the installer will have to choose a remote-interface method for the thermostat, the method should be the deciding factor for which two of the three wire colors are most function appropriate.

There is at least one, or maybe two, other threads dealing with Houghton A/C installations. Various How-tos for furnace thermostat control have been discussed at length in these. Maybe a more forum savvy contributor can provide some links to these discussions?