How can I tell if you need the 24v Power Adapter?

You can install the 24v power adapter yourself.
1. Ensure that you have started the thermostat setup in the app and you have selected the wires of your old thermostat.
2. Make sure your HVAC system is still off and click Begin in the app to start the installation of the CWA.

3. Connect the 24v power adapter wires to the Rc and C terminals of the thermostat. If the Rc terminal already has a wire connected to it, merge the HVAC Rc wire with the 24v power adapter Rc wire and connect it to the thermostat Rc terminal.

4. Once you are done installing the 24v power adapter, connect the adapter to your power supply outlet on the wall and turn it on.