Nest Ultimate main 4 wire thermostat wiring color code lift jam old
Everything You Need to Know About Your HVAC Thermostat Wiring
Trying to upgrade to Nest. What is O/B wire & why is white wire in W2/Aux? : r/Nest
Trying to replace old thermostat and ran into this. Where does the blue wire go in the new thermostat? Currently, it's plugged into the yellow slot but new thermostat has both blue