The Nest Doorbell (wired, 2nd gen) has higher power requirements than most doorbells. For some installations, you'll need to replace the transformer for your doorbell.
If you don't want to replace the transformer, and you think you'd prefer a battery powered option, you may want to install a Nest Doorbell (battery) instead.
The best way to make sure your transformer is installed correctly is to contact a licensed electrician to install the correct transformer for you.
You need a transformer that is rated for 16-24 V AC, 10-40 VA to provide enough power to your doorbell. If you've already installed your doorbell and you see a blinking yellow light on the front, your doorbell isn't receiving enough power.
How to find and replace your transformer
There are a few different locations where your transformer might be: near the main electrical panel, inside the doorbell's chime box, the garage, or the attic. You can follow the wiring from your chime to the transformer. A licensed electrician is best prepared to find and replace your transformer and install the doorbell for you.
If you don't have a transformer
If your home doesn't already have a doorbell and transformer, here are some diagrams to show how to connect the transformer to your Nest Doorbell (wired, 2nd gen). To make sure your transformer is installed correctly, contact a licensed electrician to install it for you.
If you don’t have a doorbell or transformer installed, and you think you’d prefer a battery powered option, you may want to install a Nest Doorbell (battery) instead.
Here are some common wiring configurations that may apply to your home.