How the Nest Learning Thermostat Works

Nest Installation

The moment you begin using your Nest, it begins observing your schedule and preferences to create a temperature schedule for your home.
The moment you begin using your Nest, it begins observing your schedule and preferences to create a temperature schedule for your home.
Image courtesy of Nest Labs

Nest's installation requirement list isn't terribly long. First, you'll need a WiFi network in the building, and that should include Internet access. With that in place, you can turn your attention to your existing thermostat.

Nest is designed to use the wires common to HVAC systems in homes and businesses today. Installation instructions start before you purchase a Nest:

  1. Visit the Nest support Web site and launch the compatibility check wizard. At the time of writing, you could use this link. Another option is to visit, click on "Support" and scroll down to find the Compatibility Check box and link.
  2. Remove your thermostat from its mounting frame, revealing its wires. If you need help with this, click the video link in the compatibility check wizard for hints.
  3. In the wizard, check off the abbreviations matching the ports behind your thermostat where wires are connected. Even if the wizard shows a message indicating what you have before you finish, keeping checking until all your wires are accounted for. Also, don't check off any abbreviations that don't have a wire.
  4. Click "Continue" to see if your thermostat's current wiring is compatible with Nest.

If Nest's site says your system isn't compatible, ask an HVAC professional about your options. You might want to check here to find a Nest-certified Professional in your area. If you can't find one, be ready to tell your HVAC pro what you've learned and point him or her to the Nest Labs support site. lists its supported wiring combinations here.

The second generation Nest thermostat has 10 wire connection points as opposed to original Nest's eight, so if your system wasn't compatible when the device first came out, you might want to check again. The company states that the new Nest Learning Thermostat is compatible with 95 percent of 24 volt (low-voltage) HVAC systems, up from the first generation device's 75 percent compatibility.

Once you know your home's wiring is compatible, you can purchase and install your Nest. If you're comfortable installing a light fixture or ceiling fan in your home, you can probably follow directions from Nest and install the thermostat yourself. If twisting copper wires together makes you nervous, use the Nest Certified Professionals lookup to find a professional installer in your area.

When you've installed the physical device, step through Nest's instructions to set up the software. This includes connecting to your WiFi network and your Nest account. After that, you can start using Nest to control your HVAC.

Within a week of making temperature adjustments as needed, Nest should have created a good approximate operating schedule for subsequent weeks. In addition, it never stops learning as it gathers data about you, your habits and your local weather over time.

Next, let's take a brief look at this product's advantages and challenges in the HVAC market.