If you are not comfortable working with electrical wiring or your home heating and cooling system, contact a HVAC service company to install and set up your Thermostat.
Important: Before starting work on the Thermostat or the heating and cooling system (HVAC), always switch off the power to the HVAC at the breaker box or the system's primary power switch. Verify the power is off before removing the device faceplate. Do not touch any exposed wire ends.
- Remove the faceplate or box from your old thermostat. Before disconnecting any wires, take a picture of the wiring connections for later reference.
- Look for any of the following indicators that your system is high-voltage:
- Warning labels that say 110v or 220v
- Wires labeled L1 or L2
- Wires connected by wire nuts (screw-on caps)
If you see any of those high voltage indicators, the Amazon Smart Thermostat won't work with your system.
- Make careful notes of which terminals have wires connected. Take a photo with your phone for reference, including the terminal labels.
- Remove one wire at a time. Use the stickers that came with your Amazon Smart Thermostat to label each wire with the terminal it came from. Repeat until all wires have been removed and labeled. Don't let the labeled wires fall back into the wall.
- Make sure there is a wire for the C terminal, which provides power from the HVAC system to the Thermostat. If you have no wire for the C terminal, some newer homes might have an unused wire behind the wall plate. If there is no unused wire to convert to a C wire, a C-Wire Adapter is required. We recommend the adapter compatible with the Amazon Smart Thermostat.
If you find an unused wire, label it with the C sticker, and connect the other end of that wire at your HVAC system's control panel to the C terminal, sometimes labeled as "24V" or "24 common". Then connect the end at the Thermostat to the C terminal.
- Remove the wall plate from your old Thermostat. Install the Amazon Smart Thermostat optional trim plate if you want, and then install its wall plate so the labeled wires can come through.
- When the wall plate is fastened to the wall, connect each labeled wire from the wall into the slot as directed in the Alexa app. Refer to the labels, and the picture you took if needed. After connecting, gently tug each wire to make sure they're connected. Make sure the R terminal switch is in the up position.
- Close the wire cover on the wall plate. Then align the Amazon Smart Thermostat faceplate with the wall plate and press together gently until it clicks into place.
- Turn the heating/cooling system power back on at the breaker box or switch where you turned it off.