Best Compatible?

[Milestones]

I have three wires on my old thermostat labeled D R B. 

Can anyone tell me if this is Nest compatible?

Thanks!

[zoeuvre]

Hi Milestones, 

Thanks for posting here in the Community forum and for showing interest in our Nest Thermostats. The D terminal controls your in-home dehumidifier. In that case, I highly recommend you contact a local HVAC professional for professional assistance and professional installation. Learn more about thermostat wires here in the Identify a thermostat wire article.

Let us know if you have any other questions.

Best,

Zoe