Nest learning thermostat help

[ashychuk]

I have a two stage heat pump condenser and variable speed air handler. Is the nest learning thermostat compatible for this system to work optimally?

[CoolingWizard]

@ashychuk ,

Please provide the model number of your air handler and the outside unit. Some HVAC manufacturers have proprietary systems that require their specific thermostat to unlock the advanced features.  Some of these systems can be operated by a Nest Learning Thermostat. 

AC Cooling Wizard

[ashychuk]

Trane XR17 Model #4TWR7036B1000  3-ton Two-Stage Heat Pump Condenser.

Trane Model #TEM6A0C36H31S  3-tonVariable Speed Air Handler

[CoolingWizard · Accepted solution]

@ashychuk ,

I have good news for you. Your Trane 4TWR7 has a conventional HVAC control system. You will need a Google Nest Learning Thermostat 3rd Generation in order to support 2-stages of heat pump.  All of the advanced efficiency is built into the air hander control board. 

AC Cooling Wizard

[ashychuk]

• I’m a little confused on the configuration of the wiring from the old thermostat and how it correlates with the inputs on the nest learning thermostat. Can I send you a picture of the old thermostat wiring for comparison and input?

[ashychuk]

 

[CoolingWizard]

@ashychuk ,

Your current thermostat is pretty much a standard and conventional thermostat. 
Power enters on the Red wire and is attached to R. The Green wire is attached to G. The Yellow wire is attached to Y. A Brown wire is attached to Y2. An Orange wire is attached to W-O/B. By the way, this is your heat pump control. The Blue wire gors to C.
The White wire is attached to AUX/E. Now here you have a choice to make. On the Google Nest Learning Thermostat you can put this on AUX or E.  When your heat pump in the winter time goes into defrost mode. It activates the auxiliary heat to provide back up heat while it’s in the process of defrosting. The other option is in the case of a system failure you can have that auxiliary heat wired up to E which is emergency heat, when you have emergency, you have a failure you can force the thermostat to turn on your electric auxiliary heat and the blower and keep the house from going subzero cold in the winter time. This will be a personal choice for you. 
In the Nest learning thermostat box, she will find a set of blue stickers with white letters to help you. As you remove a wire place a sticker on it. Place the RC sticker on the RED wire. Place the G sticker on the GREEN wire. Place the Y1 sticker on the YELLOW wire. Place the Y2 sticker on the BROWN wire. Place the C sticker on the BLUE wire. Place the W2 sticker on the WHITE wire. 

For your  Google Nest Learning   thermostat attach the base plate on the wall and attach your wires. 

AC Cooling Wizard

[ashychuk]

Awesome, thanks!