How to Install a Smart Thermostat

Don't let an old thermostat suck the energy (literally!) out of your home. Upgrade to a smart, easy-to-program, and energy-efficient thermostat, such as the Nest Thermostat ($246.95, Amazon). They're easier to install than you might think, and many models pay for themselves after a year.

First, before you start any installation, double-check the location of your old thermostat to ensure it's in the best place. Then, you'll need to make sure your home's heating and cooling system is compatible with a smart thermostat. Also, download the thermostat's mobile app (if available) to track your usage, set your thermostat while you're away from home, and learn how to use less energy.

What You Need

• Programmable thermostat (we used the Nest Thermostat)
• Screwdriver
• Camera or smartphone
• Joint compound
• Putty knife
• Sandpaper
• Paintbrush
• Paint
• Screws
• Drill (optional)

How to Install a Smart Thermostat

When installing your new smart thermostat, your instinct might be to put it where the old one once was—but that's not always the best option. According to Consumer Reports, your new device should go on an interior wall and away from anything that could drastically affect the area's temperature, such as direct sunlight, an air vent, or a window.

If your old thermostat was installed in a less-than-ideal place, you'll have to hire someone to reconnect the wires. After you've completed this step, it's time to install your new gadget.

Step 1: Turn Off Power

Turn off power at the circuit breaker for your heating and cooling system. If the system is running, wait until it stops. Then drastically adjust the temperature. If you don't hear the air kick on, then you know it's off.

Step 2: Remove Old Thermostat

Snap off or unscrew the existing thermostat cover. Take a picture of the wires with a camera or smartphone to remember how your system is laid out.

Step 3: Label Wires

If your old thermostat was in a proper place, use small stickers (the Nest comes with labeled stickers) or pieces of colored tape to label each wire. Then, disconnect the old thermostat backplate with a screwdriver.

Step 4: Patch and Paint

Unless your new thermostat is the same shape and size as the old one, you'll likely need to patch the wall. (Or, if you're putting your new device in a different area, you'll have to repair the wall completely.) Spread joint compound onto the wall with a putty knife. Let dry. Lightly sand the area, then paint to match the existing wall shade. Let dry.

Step 5: Attach New Thermostat

Thread the wires through the backplate of the new thermostat. Attach backplate to the wall with screws.

Step 6: Connect New Thermostat

Insert each labeled wire into its matching connector. Push the wires in until they click. Once all wires are attached, push them flat against the wall to make room for the thermostat display plate.

Step 7: Attach Display Plate

Attach the thermostat display plate to the backplate. You should hear it snap securely into place.

Step 8: Program Thermostat

Turn the power back on at circuit breaker. Then program the thermostat according to the manufacturer's instructions. A smart thermostat will learn your habits and sync to your mobile phone, allowing you to adjust your home's temperature at any point and saving you money on energy bills.