Compatability

[Aksu]

Can anyone give me some advice whether this will work without C wire adapter with smart thermostats?
Thanks


https://drive.google.com/file/d/1QPFBdcfh0jDrvN7O9CYv_uyk-wq8cPTf/view?usp=sharing 

[jb76]

Hi - Looks like you have a 5 wire thermostat harness so you should be good to go with a Nest - keeping in mind the following connections for Heat/AC:
W - Heat (typically a 'white' wire)
Y1 - Cool/AC (sends signal to turn on compressor)
C - Common wire from furnace (typically blue)
R - Control to turn on Furnace (where Nest would normally get its passive power from) - typically red color
G - Fan control (if your HVAC supports this) - typically green wire.

Note: In your photo - you have the White wire going from W to R (shared) and an O (orange wire) - not sure what that is connected to on your furnace but Nest should detect that as a Common wire to charge itself with (you could also test this Orange wire with a multimeter to confirm you are getting 24V).

J

[Aksu]

Thanks for the answer, maybe not so much clear in the photo but White is not shared.
I have these ones connected not a shared connection:
G-green
B-blue
R-red
Y-yellow
W-white
X2-black
O-orange

[jb76]

Ok - it still should work - try the Nest and confirm what it detects as it will need a minimum of the following:
W (heat)
G (fan)
R (furnace control)
Y (cooling/AC control)

*Optional but important to keep power to the Nest - a C wire (typically blue but can be any color depending on your furnace). If you have access to the furnace control board, this will tell you possibly what the additional Orange and Black wires go to. Bottom line, you have all of these required wires including X2 (black) and O (orange)...so keep the old thermostat in case and good luck!
J

[zoeuvre]

Hi folks,

Thanks for chiming in, @jb76. 

@Aksu, thanks for posting here in the Community forum and for showing interest in our Nest Thermostats. Fortunately, your thermostat wires are compatible with any of our Nest Thermostats and should be wired to the Nest Thermostat base as follows:

• Green wire to G
• Blue wire to C
• Red wire to R or RC or RH
• Yellow wire to Y or Y1
• White wire to W or W1
• Black wire to * or *OB

Also, here's a guide for the installation and setup of a Nest Thermostat. 

Let us know if that helps.

Best,

Zoe