Installing a Google Nest Thermostat

Beginner 30-45 minutes

Before You Begin

The Google Nest Thermostat works with most 24V heating and cooling systems. Before purchasing, use the Nest Compatibility Checker to verify your system is supported.

What You Will Need

  • Google Nest Thermostat
  • Screwdriver (Phillips head)
  • Smartphone with Google Home app
  • Your Wi-Fi network name and password
  • Optional: Trim kit for larger wall holes

Step 1: Turn Off Power to Your HVAC System

Important: This step is critical for your safety.

  1. Locate your circuit breaker or fuse box
  2. Turn off the breaker for your heating/cooling system (usually labeled "HVAC," "Furnace," or "AC")
  3. Verify the power is off by checking your current thermostat display is blank

Step 2: Remove Your Old Thermostat

  1. Take a photo of your current wiring - this is essential for troubleshooting
  2. Note which wire connects to which terminal (R, W, Y, G, C, etc.)
  3. Gently pull the wires out of the terminals
  4. Remove the old mounting plate from the wall

Step 3: Install the Nest Base

  1. Thread your wires through the Nest base
  2. Use the built-in level to ensure the base is straight
  3. Mark the screw holes with a pencil
  4. Drill holes if needed and insert wall anchors
  5. Secure the base to the wall with the included screws

Step 4: Connect the Wires

Match your wires to the corresponding terminals on the Nest base:

  • R (Red): Power from your HVAC system
  • W (White): Heating
  • Y (Yellow): Cooling
  • G (Green): Fan
  • C (Blue): Common wire (for continuous power)

Press down on the terminal button, insert the wire, then release. Give each wire a gentle tug to confirm it is secure.

Step 5: Attach the Display

  1. Align the display with the base
  2. Push firmly until it clicks into place
  3. Turn the power back on at the breaker

Step 6: Set Up in Google Home App

  1. Open the Google Home app on your phone
  2. Tap the "+" icon and select "Set up device"
  3. Choose "New device" and select your home
  4. The app will search for your Nest Thermostat
  5. Follow the prompts to connect to Wi-Fi and configure your schedule

Step 7: Configure Your Preferences

During setup, you will configure:

  • Your preferred temperature range
  • Home and Away temperatures
  • Schedule preferences (or let Nest learn your habits)
  • Eco temperatures for energy savings

Troubleshooting

  • No power: Check that the C wire is connected, or consider a Nest Power Connector
  • System not responding: Verify breaker is on and wires are secure in terminals
  • Wi-Fi issues: Move your router closer or check for interference
  • Short cycling: This may indicate a wiring issue - recheck your connections