My old system has four wires that went to labels RS-(green wire), RS+
(blue wire), VG (white wire), and V+ (red wire). I have no idea how to
connect it to my Nest thermostat.
I was afraid that might be the case. That makes me so sad, I really
enjoy my Nest products. I will reach out to a pro installer to see if I
can get at least one of my two nest thermostats back in use.
Thanks so much for the response. My thermostat is Carrier and the model
is a Comfort Zone II. I took a picture of it but can't find an option on
here that allows me to attach it.