We have a NEST thermostat in our home and would REALLY like to transfer that technology to our future RV. Our future RV is a Georgetown 364TS class A, gas.

In reading the installation manual for the NEST it seems to be a possible match, depending upon what thermostat you have now. Your RV isn't so much the issue as what you presently have as there is a very wide range of thermostats in use by RV manufacturers. Some still use the simple, 2 wire thermostats that take power from the furnace and just supply an open or closed connection to the furnace which then heats or shuts down. Others have a telephone, RJ11 connector with 5 wires which controls both air conditioner and furnace, via a control circuit board located in the air conditioner. There are several other variations of thermostat and devices and there are also several brand names that are not all exactly alike. If you share what thermostat you have now, it may be possible to convert, but we need more information to say.

Bigger issue than the simple wiring between the t-stat and the devices, is the connectivity issues of devices like nest. Most of their optional functionality goes out the window without an internet connection. If you plan to have a mobile hotspot, always powered and providing connection to the t-stat, then they function much as advertised. If not, then no, they won't perform as advertised.

I believe that most home units ( at least every one i've installed or repaired ) use 24 volts off the system. The RV systems run off 12 volts. It says on page 3 of install manual that nest is compatible with 95% of 24 volt systems.

Edited December 26, 2016 by Ranger Smith

We have the Honeywell wifi 9000 and love it. My wife loves sitting in her chair and warming up the bedroom. It uses a wallwart to power the thermostat.

  On 12/26/2016 at 7:16 PM, Ranger Smith said:

I believe that most home units ( at least every one i've installed or repaired ) use 24 volts off the system. The RV systems run off 12 volts. It says on page 3 of install manual that nest is compatible with 95% of 24 volt systems.

Yep, that's the real problem with attempting to use a household 'stat. I suppose one could use a 12/24 convertor to obtain 24VDC if everything else worked out. They are sold on Amazon.

Edited December 27, 2016 by RayIN

I have used 3m Filtrete Radio Thermostats ever since they first came out. The units I have say "connect to 24v supply" but they also have battery back up ( which won't run the wifi module). In talking with their tech I found that the 24v compatibility is the norm but their units will work fine on as little as 8 volts. I just ran a 12v line from a nearby RV source and connected it to the thermostat and it has worked fine for year. Might be worth a call to nest tech support to ask the usable voltage range that they will work on.

Yes, I would like a nest system in my RV but what I have lets me check on temps when I am away from it (for our dog's sake). We just returned home after 10 days at our kids for the Christmas/New years events and the whole time I was able to check and control it from 500 miles away.

My existing thermostat has 3 wires. 12 v+ common  12 v neg. Trying to hook up a nest thermostat. says no power to yellow wire

Edited September 16 by Thehorseshoer

My daughter got me a NEST for Christmas, NOOOOOOOOOO it will NOT work in MY (might yours, mines a 12 Volt On/Off type) RV. Its geared more towards residential 24 Volt 5/6 wire, while many RV's (not all) are straight 12 Volt On/Off unit like mine. Sure a person could modify and electronically rig up a 12/24 volt system and/or adapters etc and make it work in an RV, but short answer is no its geared more towards 24 volt systems. If you happen to have a more complex heat pump or mini split arrangement etc etc that uses a residential type 5/6 wire 24 volt T Stat, now that's a different story, if so Id go for it.

But most anything is possible with electronics. I like its concept in a home however and may use it there. I happen to have a DUAL FUEL system, Heat Pump 40 degrees and above but Natural Gas High Efficiency below 40. My current set up has 2 extra wires (from outside thermometer) into my Honeywell Smart T Stat to monitor outdoor temp, but when I called NEST and asked how/where to attach those two extra wires they had the deer in the headlights response and said I had to get a certified NEST installer do it...…..   

John T 

Actually the Nest is powered by 24VAC not 24VDC, so you would need a transformer such as a doorbell one that converts 110AC to 24VAC OR there are converters out there that convert 12VDC to 24VAC  for CCTV cameras and I believe you would have to put that power in on the Common C wire of the Nest? I am still working on it but I will get it figured out soon enough

link:  https://powerstream.com/inv-12dc-24vac.htm

IF you want computer control thermostat / Home automation then look at systems that do not rely on a cloud based engine.

Here is a thermostat that uses 24v or 4 AA batteries. It uses zigbee to communicate: https://www.centralite.com/products/pearl-thermostat

Here is a Home automation hub that is local and can be used to control the thermostat and other things : https://hubitat.com/

Not as simple as Nest or EcoBee but can be a fun little hobby for those that like to mess with stuff.

Speaking of Ecobee thermostats, this article explains how the man adapted an Ecobee for use in their MH.  Perhaps it may be useful in your project. That  particular Ecobee SI model is obsolete/no longer available since the article was written.  https://www.janeandjohn.org/pages/Ecobee1.html

Edited November 6 by Ray,IN