Step-by-step Instructions

mportant: This illustration is only an example. Each system’s wiring is different. 
You must get your own custom wiring diagram with our Compatibility Checker. 
ncompatible wiring 
igh voltage wires 

f your thermostat is labeled 120V or 240V or has thick wires with wire nuts, your 
system is high voltage and isn’t compatible with the Nest thermostat. Do not 
connect the Nest thermostat to high-voltage wires. 
Learn more about high voltage wires 
Stranded wires 

Nest thermostats are not compatible with stranded wires. Do not connect the Nest 
Thermostat to stranded wires. 