Nest Model G4Cvz Wiring Diagram. The nest learning thermostat is designed to work even if your home doesn't have a common c wire, but installing a new c wire or the nest power connector may be required in some cases. I have the wires from a 24 volt transformer that i would like to connect to the thermostat so that the battery is kept charged.

Connect wires use the wiring diagram you got from the compatibility checker in step 4 to connect your system wires to the nest thermostat. You may need to have some female spade terminals handy for this step if you don't already have them. Installation usually takes 30 minutes or less.