Review: Nest Learning Thermostat (second gen) is worthy of all the buzz

The Nest thermostat has been hyped almost as much as the Segway electric vehicle. And to my great surprise, it’s worthy of the attention. The Nest is the absolute best thermostat on the market, and I’d buy one in a heartbeat—if only I could tie it into my home-control system.

But the Nest doesn’t play well with others, so I’ll stick with the thermostat that came with my Vivint home-control system. It’s big, boring, and ugly; but as I explained in the introduction to this review roundup, it’s even more intelligent than the Nest.

The Nest is a beautifully simple piece of hardware comprised of stainless steel and real glass. When you consider that nearly every home has a thermostat on its wall, you have to wonder why no one ever thought to make one that’s not only smart and easy to use, but also so beguilingly attractive to look at. The Nest makes even thermostats with touch-screen user interfaces look primitive.

And the Nest’s beauty is more than skin deep. Its designers put great thought into every aspect of its design, beginning with homeowner installation (it’s easy, but if you’d prefer someone else handle it, Nest’s concierge service will do it for you for $119, plus $25 for each additional installation if your home has multiple temperature-control zones).

Programming is optional 

Unlike most advanced thermostats, programming the Nest is entirely optional. While this is the feature that generates most of the hype, I was far more impressed with the Nest’s industrial engineering and user interface than its self-learning capabilities.

The Nest is equipped with a motion sensor, which it uses to detect when you’re home and when you’re away. After a while, it will automatically turn your HVAC system on and off in accordance with your routine comings and goings. You can also adjust the temperature manually when you go to bed and when you leave the house, and the Nest will remember these patterns.

When you’re away from home, its default setting won’t turn your heater on unless the interior temperature drops to 50 degrees, and it won’t turn your air conditioner on at any temperature. You can change these trigger temperatures at the thermostat, by logging into your Nest account from a computer, or by using the Nest mobile app on your Android or iOS device. The mobile apps are free, and there are no monthly service charges.

The drawback to a “learning” thermostat like this is that it doesn’t react until you’re home. If you program your day-to-day schedule, as opposed to letting the thermostat and motion sensors do it, you can set heating and cooling times in advance of when you’ll arrive, so that your home is already at the desired temperature when you arrive. The other alternative is to use the Nest’s web portal or mobile app on your way home and manually adjust the temperature before you get there.

The Nest web portal 

Unlike some programmable thermostats, which are limited to two or four time/temperature triggers per day, the Nest will let you create as many heating and cooling events as you want for each day of the week.

But if you establish your own schedule, it will override the Nest’s learning capabilities and control your HVAC system pretty much like any other high-end programmable thermostat.

A green leaf is displayed on the thermostat, the web portal, and the mobile app when the Nest considers you to be saving energy. Saving energy is defined as the HVAC system being off or when the trigger temperature for cooling is 83 degrees or higher, and the trigger temp for heating is 62 degrees or below. The thermostat will automatically turn your heater on when the interior temperature reaches 40 degrees to prevent frozen pipes.

The Nest shows the current indoor temperature and the programmed target temperature on its display, but the current outside temperature is reported only on its mobile apps and web portal. A company representative, however, told us the Nest takes the weather forecast into account when controlling any heat pumps that might be installed in your home (heat pumps don’t operate efficiently under very cold conditions).

The Nest is very useful for measuring your energy consumption, because it takes into account the fuel your furnace uses (natural gas, propane, electricity, oil, or geothermal), how the heat is distributed (forced air, radiant floor, radiator), whether or not you have air conditioning, and several other factors.

The Nest’s retro, round look belies the high-tech electronics inside. It can be mounted either directly to the wall or to a junction box, if there’s one behind your wall (since the wiring is low voltage, many builders simply poke a hole in the drywall; that’s what mine did). Most photographs of thermostat the device by itself, but since you’ll likely be replacing an existing thermostat of a different shape or size, Nest Labs thoughtfully provides a large trim plate to cover any holes or paint holidays.

As large as the trim plate is, it wasn’t big enough to cover all the holes previous thermostat installations left in my wall (I’ve reviewed more than a few). If you buy a Nest, do yourself a favor and apply some spackling compound and paint to any old holes; the trim plate really detracts from the thermostat’s beauty.

Installing the Nest

The Nest comes with a well-written, illustrated booklet that steps you through the installation process. You’ll find adhesive labels inside the book for labeling the low-voltage wires coming from your HVAC (heating, ventilation, air conditioning) system. Most thermostat manufacturers provide such labels these days, so my wires were already identified from a previous installation.

If you’re mounting the Nest directly to the wall, the backing ring has a built-in bubble level to help you mount it straight (brilliant!). The backing ring has a hole in the middle that you feed the wires through. When you push down the binding clips on the ring and insert the bare wires, the clips remain depressed to let you know you’ve made a solid connection. The middle of the ring is recessed, so you can tuck in any excess wire.

The last steps are to mount the Nest to the backing ring (an electrical connection is established when a tab on the back of the Nest plugs into a socket on the front of the ring) and to turn the power back on. The Nest draws power from your HVAC system, but it also has a backup battery that recharges itself from the same source.

The Nest prompts you to connect it to your wireless network the first time it powers up, so that it can access the Internet. As high tech as the Nest is, it doesn’t have a touch-screen display. You navigate its user interface by rotating the stainless steel outer dial and pushing on either the ring or the glass face to make your selections. To enter information such as passwords, you must rotate the dial to select letters displayed on the outer edge of the screen and then press to spell out the letters, numbers, or symbols.

Once you’ve added the Nest to your wireless network, you go back to your computer and establish an account on Nest’s website. The Nest will automatically connect to this website, download and install the latest firmware, and then generate a passcode that you type into your web browser to finish pairing your thermostat with your online account.

The Nest’s dial turns blue when your HVAC system is cooling and red when it’s heating. A proximity sensor lights up its display when you approach; the rest of the time, the display is blank to save power.

It seems counterintuitive that the current temperature is rendered so small until you push on the thermostat and a pair of arrows appear, bracketing the larger target temperature. As you would expect, pushing on the top half of the dial raises the target temperature, while depressing the lower half lowers it. Rotating the Nest’s ring calls up a set of menus for controlling your HVAC system manually, for programming the Nest, and for revealing an amazing number of details about the Nest itself, including energy consumption, current battery level, network settings, and more.

Final Thoughts

The Nest is a beautiful piece of hardware that’s packed with great technology. While I think the self-programming aspects of this thermostat border on silly, its looks and its overall feature set justify its price tag—which really isn’t all that high compared to the second-place Venstar T5800.

If you don’t have a home-control system and don’t anticipate installing one, the Nest is the best thermostat on the market today.

Note: This review is part of a three-product roundup. Click here to read more about programmable thermostats in general and to find my reviews of two other products: The Honeywell RTH8580WF programmable thermostat and the ColorTouch T5800 touchscreen thermostat.