A:Answer Once you have the right information, the installation was easy and straight forward coming from a guy that is not too handy. Just like others that have had the issue of No C wire behind the thermostat, I turned to purchasing this power connector. The following I learned from doing a ton of research and hopefully it will help out many others. Turn off the power to the furnace. If you only have 1 zone control in your home (meaning you only have 1 thermostat in your home), you wire this power connector to the furnace board. If you have 2 zones or more (meaning more than 1 thermostat), you wire the power connector to the zone controller, not the furnace board. If you have more than 1 zone, you will need 1 power connector for each zone that has a Nest thermostat installed. The Zone controller for me was a rectangular box attached to top of my furnace (see my image, my zone controller is the rectangular box that says Lennox). I don't know what shape or where yours will be located. Once you open your zone controller cover, you will see terminals (where wires are connected from the thermostats) for each zone in your home. Each terminal should be labeled. In my image, I have 2 zones (2 thermostats). Zone 1 you will see the power connector wired to it because zone 1 is my Nest thermostat. I did not add a 2nd power connector to Zone 2 yet, because I still have a non Nest thermostat installed for my zone 2. I will purchase another Nest thermostat and a 2nd power adapter and wire that to the zone 2 on my zone controller.
