Wiring Up a Nest

This weekend I finally broke down and installed a Nest thermostat in my house. They have a nice compatibility wizard which does a pretty good job of showing you how to wire up your Nest based on the wires you can see in your existing thermostat. There were two gotchas that their wiring diagram didn’t cover. Here is a picture of the old thermostat (a Rodgers-White):

  1. Notice that there were two W wires. I’m not to sure what is up with that, I suspect that that one wire leads up to the humidifier. I ended up splicing the two wires together with a marette, and then connecting the spliced wire to the W connection on the Nest. This was not documented anywhere on the Nest website.
  2. The other thing that the Rc post on the thermostat was jumpered over to the Rh post. All I had to do here is remove the jumper and just plug the wire into the Rh connection on my Nest. This issue was documented on the Nest website.

All in all, the process was quick and easy. Now to see if the Nest actually makes a difference in my energy bill.