Can I replace a Carrier TP-PAC01-A Thermostat with a Nest

[NM98]

I have a new Nest Learning Thermostat (T3018US).  My current thermostat is a Carrier TP-PAC01-A.  It only has 2 wires coming to it from the wall (V+Red, VgBlack).  It is not compatible as is with the Nest which needs 6 wires (Y,G,Rc,W,C,Rh).  Is there any way I can make my current thermostat work with the new Nest.  I included a picture of my current thermostat opened up.

[Houptee]

Its a proprietary tstat that communicates on the wires like ethernet.

You can go to the furnace and take off cover and there are standard screw terminals for regular tstats and you would move the wires to those screws if you want to use the Nest.

There is a decal on back of the cover with wiring diagram shows tstat wiring or if you have the manual for the system look in there.

You might need to pull a new cable with 5 or 8 conductors if the one there now doesnt have enough wire colors in it.

Is this 2 stage cooling and 2 stage heating? If so you need the Nest Learning for systems with stages.

[aatienza]

Hey NM98,

Checking in — we hope you've got the answer you're looking for. Let us know if you have more questions in mind.
 

I appreciate the help, Houptee.

Thanks,

Archie

[NM98]

Hi,

Thanks for the quick reply.  I figured the 2 wires coming to the thermostat from the Carrier furnace / blower in the attic was a Carrier digital signal (like ethernet as you say).  Unfortunately the attic is 2 stories hire than the thermostat and I don't want to pull the 6+ wire HVAC cable down since I'd have to walk on the beams which is a bit dangerous at that high a level.  I don't have plywood put down all over the attic.  What I was wondering is in there is a converter I can put near the thermostat that I can convert the Carrier 2 wires back to the 5-6 wires that the Nest Thermostat needs.  The Carrier Edge thermostat I have is already programmable.  What I really like about the Nest or Echobee is that you can put the remote temperature sensors in other rooms to control the temperature.  I included a picture of the Carrier board where the red and white wires are the ones that run downstairs to my thermostat.

[Jenelyn_O]

Hi there,

Chiming in — I'm sorry for the delay. I just want to confirm if you're still encountering the issue. Please let me know, as I'll be willing to assist you further. 

I appreciate your help, @Houptee, and Archie.

Best,

Jenelyn

[Jenelyn_O]

Hi there,

I wanted to follow up and see if you still need help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Best,

Jenelyn

[Jenelyn_O]

Hi there,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this thread in 24 hours.

Best,

Jenelyn