Best Smart Thermostat
With its round, metallic design, the Nest Learning Thermostat made all other thermostats seem old and outmoded in an instant. Three years after the Nest’s debut, there are finally thermostats that can approach it in style and functionality—but the third-generation Nest is still the leader in the category. The Nest hardware continues to offer the best combination of style and substance, its software and apps are solid and elegant, and it’s easy to change the temperature from your phone or computer, so you won’t have to get up from your cozy spot on the couch to mess with the thermostat.
We spent more than a month trying out the top three thermostats in this category, including a dozen-plus hours to actively test the thermostat hardware and perform remote tests using their accompanying mobile apps.
The Nest Learning Thermostat is our top pick for the second year in a row. It has a sleek, round look, is easy to install, programs itself, and is the center of Google’s ever-growing Works with Nest smart-home ecosystem. Its software has improved over the past two years, but it’s no longer the only smart thermostat in its class.
Note: We tested the second-generation Nest. The third-generation Nest has a larger screen and a thinner body, and offers a new feature called Farsight that wakes the screen at a greater distance so you can see the temperature or time. The Nest’s core feature set remains the same, so although we are working on testing the third-generation version, the Nest is very likely to remain our pick.
The Ecobee3 doesn’t have the retro cool look of the Nest or even the Honeywell Lyric—its black rounded-rectangle design and slick touchscreen interface make it feel like someone mounted a smartphone app on your wall. But its support for remote sensors makes it appealing if your thermostat isn’t in the best part of your house to measure the temperature. If you have a large, multistory house with a single one-zone HVAC system, there can be big temperature differences between rooms. With Ecobee’s add-on sensors (you get one for free with the unit and can add up to 32 more), the thermostat will use the sensors’ occupancy detectors to match the target temperature in occupied rooms, rather than just wherever the thermostat happens to be installed.
Table of contents
- Why a smart thermostat?
- Who’s this for?
- How we picked and tested
- Our pick
- Who else likes it
- Some minor drawbacks
Why a smart thermostat?
If you upgrade to any smart thermostat after years with a basic one, the first and most life-changing difference will be the ability to control it from your phone. Think about it: no more getting up in the middle of the night to turn up the A/C. No dashing back into the house to lower the heat before you go on errands (or vacation). No coming home to a sweltering apartment—you just fire up the A/C when you’re ten minutes away.
Technically, thermostats have been “smart” since the first time a manufacturer realized there could be more to the device than a mercury thermometer and a metal dial. For years, the Home Depots of the world were full of plastic rectangles that owed a lot to a digital clock: They’d let you dial in ideal heating and cooling temperatures and maybe even set different temperatures for different times of the day and days of the week.
The thermostat world changed with the introduction of the Nest in 2011 by Nest Labs, a company led by Tony Fadell, generally credited to be one of the major forces behind Apple’s iPod. This was a stylish metal-and-glass Wi-Fi-enabled device, with a bright color screen and integrated smartphone apps—in other words, a device that combined style and functionality in a way never before seen in the category.
The Nest got a lot of publicity, especially when you consider that it’s a thermostat. Within a few months, Nest Labs was slapped with a patent suit by Honeywell, maker of numerous competing thermostats.
But once the Nest was out there, it was hard to deny that the thermostat world had needed a kick in the pants. And three years later, not only have the traditional plastic beige rectangles gained Wi-Fi features and smartphone apps, but other companies have entered the high-feature, high-design thermostat market, including the upstart Ecobee and the old standard Honeywell.
The fact is, a cheap plastic thermostat with basic time programming—the kind we’ve had for two decades—will do a pretty good job at keeping your house at the right temperature without wasting a lot of money, so long as you put in the effort to program it and remember to shut it off. But that’s the thing—most people don’t.
“The majority of people who have a programmable thermostat don’t program it, or maybe they program it once and never update it when things change,” said Bronson Shavitz, a Chicago-area contractor who’s installed and serviced hundreds of heating and cooling systems over the years.
These new thermostats are smart because they spend time doing the thinking that most of us just don’t do: turning themselves off when nobody’s home, targeting temperatures only in occupied rooms, and learning your household schedule through observation. Plus, with their sleek chassis and integrated smartphone apps, these thermostats are actually fun to use.
Nest claims that a learning thermostat (well, its learning thermostat) saves enough energy to pay for itself in as little as two years.
Who’s this for?
Get a smart thermostat if you’re interested in saving more energy and exerting more control over your home environment. If you like the prospect of turning on your heater when you’re on your way home from work, or having your home’s temperature adjust intelligently without having to spend time programming a schedule, these devices will do the job. And if your thermostat was placed in a prominent place in your home, well, these devices just look cooler than those beige plastic rectangles of old.
If you already have a smart thermostat, like a first- or second-generation Nest, you don’t need to upgrade just yet. And if you have a big, complex home-automation system that includes a Z-Wave thermostat already, you may prefer the interoperability of your current setup to the intelligence and elegance of a Nest or similar thermostat.
If you don’t care much about slick design and attractive user interfaces, there are cheaper thermostats that offer Wi-Fi connectivity and some degree of scheduling flexibility. Their hardware is dull and their interfaces are pedestrian, but they’ll do the job and save you a few bucks.
The devices we looked at are designed to be attached to existing heating and cooling systems. In fact, in some cases they work better with older HVAC systems than new ones. If you’re installing a new heating and cooling system in your home, HVAC contractor Shavitz strongly recommends that you ask your installer about the smart thermostat offered by the company that manufactures that system. Most manufacturers now offer Wi-Fi thermostats of their own, and while they’re generally not as stylish as the models we looked at, they have the advantage of being designed specifically for that manufacturer’s equipment. That has some serious benefits, including access to special features and a deep understanding of how specific equipment behaves that a more general thermostat can’t have.
How we picked and tested
As we researched this category, we decided to limit ourselves to smart thermostats that combined interesting design with smartphone access and intelligent scheduling. There is a much larger category of thermostats that look old-fashioned and feel very much like the technology of the past with some new features stuck onto them, rather than a true rethink of the thermostat. We decided to focus on high-tech, smart devices, the category almost defined by the introduction of the Nest. As Megan Wollerton of CNET put it, the “utilitarian design doesn’t appeal to the same category of consumer as the Nest.”
CNET has covered this category well, with reviews of the major players and continual updates. Consumer Reports has also chimed in, but we question their priorities. In our last review of this category, we referred to CR’s take as “very wrong.” That may be a bit harsh, but their list of top remote-access thermostats seems to massively undervalue the designs and interfaces of the Lyric, Nest, and Ecobee3, preferring more conventional models from Honeywell, American Standard, and Trane. Many of those high-ranking models are also much more expensive than the three models we tested and designed to work with specific HVAC systems.
By eliminating expensive, proprietary, and non-learning smart thermostats, we ended up with three finalists: the second-generation Nest, Ecobee’s Ecobee3, and Honeywell’s Lyric. We installed each ourselves and ran them for more than a week each in routine operation. Testing was done in the fall in a Northern California home with a single forced-air furnace, so we didn’t test air conditioning, dehumidification, or multiple zones. Where rewiring was needed, although we did consult with a contractor, we ended up going to our local hardware store, buying a roll of thermostat wire, and re-wiring the heater ourselves. Our testing considered ease of use in adjusting the temperature, setting a schedule, and using smartphone app features.
Our pick: The Nest Learning Thermostat
Note: We tested the second-generation Nest. In early September, Nest Labs launched the third-generation device, which has a larger screen, a slimmer profile, and the ability to show the temperature from across the room. Since its core features are as good as those of the previous version and the price hasn’t gone up, we now recommend the third-generation Nest, though if you can find the second-generation Nest for cheap it’s still a good buy.
The $250 Nest Learning Thermostat is the leader of this category for a reason. Its learning mode automatically programs the thermostat based on your home and usage, its industrial design is the best, and it works with many other smart-home devices. The Nest offers the best combination of style and substance, its software and apps are solid and elegant, and it integrates with more smart devices than any of its competitors—for now.
The industrial design of the device is strong: a metallic ring with a black front and a circular LCD screen in the middle. The on-device interface is elegant—my favorite of the three we tested—with every setting controlled by either a push on the face or a spin of the ring. The display shows red when heating, blue when cooling.
The Nest’s onboard software is pretty smart, too. It learns the thermal dynamics of your space and estimates how long it will take to reach a target temperature, and displays that. Its heating and cooling schedules can be set to hit a specific temperature at a specific time, rather than just turn on and off at that time. (For example, I set the Nest to get my house to 70 degrees at 6:45 a.m. On a very cold night it would turn on extra early just to make sure I didn’t get cold toes when I got out of bed.)
The Nest’s learning mode puts it above its competitors. It’s constantly aware of the temperature adjustments you make on the devices—the point is to reduce the need to manually program the thermostat by learning what you like on its own. Coupled with an occupancy sensor that can tell when nobody’s around (in theory), the Nest can learn from your patterns and create its own schedule without any work from you.
I found that the Nest’s learning system worked fairly well, but creating manual schedules is also a breeze. The excellent Nest app (for iOS or Android) lets you program specific times and temperatures with a few taps. And as HVAC contractor Shavitz told me, you can’t discount the psychological power of Nest’s green leaf icon, which motivates you to forgo a little comfort and dial the temperature down just a little bit more in order to save energy.
Installing the Nest was easy. After removing my previous thermostat, I screwed on the the Nest baseplate and was able to follow the included instruction pamphlet to slide the correct wires into the labeled terminals. The Nest can charge its built-in battery via your existing thermostat wiring, and I never had a problem with it running out of battery power during normal use, though if you have a power-providing common wire among your thermostat wires, that will provide extra insurance. Nest also offers an online compatibility checker and phone support for installation help.
Nest’s mobile app is easy to use and lets you set the target temperature as well as program an entire day-by-day, hour-by-hour schedule, if you’re so inclined. There’s also a website that lets you do all the same stuff, so if you’re at your computer you don’t need to get your phone in order to change the temperature.
Nest Labs, which is now owned by Google, keeps expanding its Works with Nest program, which promises interoperability with other smart appliances and services, from lightbulbs, Nest Cams, and smart locks to universal remotes, washing machines, fitness bands, and Google Now. The Works with Nest program has the potential to make the Nest the best choice for people who want their thermostat to interact with other home-automation products. So far, a lot of the integrations are pretty gimmicky, but that may not be the case for long.
Who else likes it
CNET’s Megan Wollerton gave the third-generation Nest four and a half stars out of five, saying, “Nest is still our choice for best overall smart thermostat, but it isn’t massively different from the second-gen model and the gap is narrowing as other brands introduce solid competitors.” Wollerton pointed out that the Nest system still lacks remote temperature sensors, unlike the Ecobee3. (In 2012, CNET gave the second-generation Nest five stars out of five.)
PC Magazine also loved the Nest, giving it 4.5 out of five. Wirecutter editor in chief Jacqui Cheng, writing for Ars Technica in 2012, gave the first-generation Nest a high endorsement: She said she’d be sure to take her Nest with her the next time she moved. Engadget gave the Nest 95 out of 100 in a similar rave.
Because the second-gen Nest came out in 2012 and the third-gen version arrived in September 2015, very few reviews of the Nest compare it directly with its newest competition though almost all reviews of other smart thermostats mention the Nest.
In 2014, CNET reviewed both the Ecobee3 and the Honeywell Lyric, and while the reviews were generally positive toward both products—feelings we wholeheartedly share—they indicated that the Nest was still tops in the category. The Lyric “can compete on features, but doesn’t match the Nest’s intuitive design,” while the Ecobee3 is depicted as still “clos[ing] in on Honeywell and Nest.”
Some minor drawbacks
The Nest’s greatest weakness is its lack of external sensors. It can connect with the Nest Protect smoke alarm in order to act as an additional occupancy sensor, but you can’t feed the Nest temperature or occupancy data from other locations without buying expensive third-party hardware. This can be a problem if your Nest is in an infrequently used hallway, or on a different floor from the one you most often use. You can get around this by buying the $300 WallyHome Sensor Kit, which gives the Nest access to temperature data from six different locations in your house, and other Works with Nest devices can feed the Nest occupancy data. But Nest probably shouldn’t punt the important job of measuring temperatures and occupancy throughout a house to a third party.
One of the major drawbacks of the Nest, like other smart thermostats, is that it’s essentially a small computer that requires power to operate. If your heating and cooling system is equipped with an energy-bearing “common wire” (also called a C-wire), you won’t have any concerns about power. The problem is, common wires are not very common—Shavitz said that he finds it “fairly prevalent” that no common wire is available. Both the Nest and its competitor the Honeywell Lyric can manage to charge themselves by stealing power from other wires, but that can cause some serious side effects, according to HVAC contractor Shavitz. He said that old-school furnaces generally are resilient enough to provide power for devices like the Nest and the Lyric, but high-tech circuit boards on newer models can be more prone to failure when they’re stressed out by the tricks the Nest and Lyric use to charge themselves without a common wire.
Bottom line: You may be able to run the Nest without a common wire, but it’s probably safer to get a contractor to install one if you don’t have one already, especially if you have a newer furnace—this typically costs about $100 to $150 depending on your location. (The Ecobee3 doesn’t even try to use this trick—it requires a common wire and comes with an entire wiring kit to add one if you don’t have it.)
Long-term test notes
Several Sweethome and Wirecutter editors have used first- and second-generation Nest thermostats, in some cases for years, in areas with hot summers and cold winters (Philadelphia, Chicago, and Houston). Everyone loves their Nests, but two editors noted some issues with newer HVAC equipment until they installed a common wire. And almost everyone wishes it came with remote sensors. Most work from home and have the Nest in a hallway that doesn’t see much foot traffic, so it keeps thinking nobody’s home. Still, every editor we talked to would buy the Nest again.
The next best thing (for larger homes)
If you have a large home with a single HVAC system, or you want to be able to measure the temperature in rooms other than wherever your thermostat happens to be, consider the Ecobee3.
The $250 Ecobee3 is not a friendly round widget like the Nest and the Honeywell Lyric. It’s a black slab, a touchscreen that you interact with as if you were using a smartphone app. If your sense of style is more high-tech than homey, you might even prefer it. Because it’s driven by a touchscreen, interacting with the Ecobee3 is much less tactile than turning a ring on the Nest or the Lyric. There are some advantages, though—entering my Wi-Fi password was much easier on the Ecobee3, which can display an on-screen keyboard when it needs to.
Ecobee’s newest version, introduced in late July 2015, has built-in hardware to support Apple’s HomeKit, which allows for Siri-voice control and coordinated actions with other HomeKit enabled devices. We haven’t tested the HomeKit-enabled version yet, but think turning down your heat and turning off your smart lights at the same time. HomeKit is a new universal framework for smart gadgets and there aren’t a huge number products that support it yet, but if you’re interested in HomeKit-enabled devices, Ecobee3 is one to consider.
Beyond its touchscreen interface, the Ecobee3’s biggest strength is its remote sensors. It comes with one battery-operated sensor that you can place elsewhere in your house. The sensor monitors both temperature and occupancy, so the Ecobee3 can better detect who’s in your house and what the temperature is throughout—not just where your thermostat is. If you’re downstairs and it’s cold, a thermostat installed at the top of a staircase might think nobody’s home and it’s plenty warm. With a remote sensor downstairs, the Ecobee3 can realize that it’s not warm enough down where the people are, and adjust accordingly. You can purchase additional sensors for the Ecobee3—up to 32 of them—in packs of two for $80.
Ecobee3’s large touchscreen gives it an advantage over other smart thermostats, and it definitely attempts to use the space. Tap the cloud icon and you’ll get a local weather forecast, for instance. I like how it displays the current temperature in very large type, with the target temperature in a smaller circle off to the right. It also displays the outside temperature on the idle screen along with the current indoor temperature. There’s probably more Ecobee could do to take advantage of the space, but I like the flexibility.
The Ecobee3 requires either a common wire or the installation of its included power-extender wiring kit (which cleverly saps power from your heater and sends it over your existing thermostat wiring, so you don’t need to run new wire). Depending on your home’s wiring, this might be no big deal, or it might be a showstopper. In my case, I ended up having to rewire my heater in order to install the Ecobee3. It took me only a couple of hours, but the Ecobee3’s power-consumption needs make it more finicky than its competitors if you don’t have a common wire.
Reviews for the earlier Ecobee3 (without HomeKit) are pretty strong. CNET’s Megan Wollerton gave it 3.5 out of five. She liked the performance of the thermostat but found the apps glitchy. Adam Miarka at Zatz Not Funny also liked it, especially the remote sensors, and Steve Jenkins’s review and follow-up both say it’s better than the Nest or the Lyric—though he’s a longtime user of previous Ecobee products.
Unfortunately, I encountered numerous quirks with Ecobee3’s smartphone app and its website. The app quit repeatedly, and when it did work, it didn’t feel especially responsive. It did a good job of emulating the same interface I saw on the Ecobee3 screen, though. I also ran into a problem where the Ecobee3 thought I was living on Eastern Time, despite it knowing I was in California, and turned on my heater three hours too early. (Blogger Steve Jenkins seems to have run into it too; Ecobee says it’s changing the way time zones are set to avoid this problem.) I also found that the Ecobee3 screen was sometimes hard to read, either because it seemed too dim in bright light or because of glare off its shiny surface. I also couldn’t get used to the fact that the Ecobee3 often seemed to be displaying the wrong temperature, though when I looked closer it turned out that the main thermostat was displaying an average temperature based on its own location and the room containing its remote sensor.
Because its remote sensors are so useful and easy to add, the Ecobee3 is a compelling choice for people with large, multistory houses that don’t have multiple zones or HVAC systems, since your thermostat isn’t always in the best spot to measure the temperature of the rooms you use more often. The Nest is still better for most people, but the Ecobee3 is the closest competition.
The competition (is much better than it used to be)
Without any hardware releases from Nest in the past two years, the competition has picked up the slack a bit. In addition to the Ecobee3, there’s another stylish, intelligent device that threatens to upset the Nest’s ownership of this category. Neither has quite toppled the leader yet, but Nest doesn’t have much more time to keep resting on its laurels.
Like the Nest, Honeywell’s Lyric is round, with a spinning ring for setting the temperature. The Lyric covers more wall than the Nest, but it also doesn’t stick out as far.
The Lyric was the easiest of the three devices to install, though I found it easier to attach wires on the Nest and the Ecobee3. The smartphone app walks you through all aspects of installation, with clearly written (and well-illustrated) instructions. Once you’ve wired it up, Lyric broadcasts its own Wi-Fi network, which you connect to with your smartphone. Then you use the Lyric app to enter in your local Wi-Fi network’s name and password, saving you from having to laboriously “type” it via clunky thermostat hardware, à la the Nest.
On the front of the Lyric there are two touch-sensitive buttons and two display areas: The large circle at the center displays the current temperature (though if you tap the weather-forecast button, it shows you a local forecast). The smaller one at the top shows the target temperature and indicates if you’re in heating or cooling mode. These displays are always on, which I liked. The Nest turns its screen off to save power unless you’re in close proximity; it was nice to be able to glance across the room and see the temperature right on the Lyric’s display.
While the Nest’s control ring glides effortlessly, I found the Lyric’s unpleasant to turn—it was harder to grip and offered much more resistance. I also prefer the Nest’s all-black front to the Lyric’s white front with black display circles, but that’s a matter of taste. Displaying the current temperature more prominently than the target temperature was a good choice—after having used both the Lyric and the Ecobee3, I find it preferable to Nest’s heavy emphasis on the target temperature.
The Lyric’s major selling point is that “it doesn’t need to learn a routine,” according to the Lyric website—making it a bit of an anti-Nest. Instead of learning your routine, the Lyric uses its own occupancy sensors as well as connected smartphones to get an idea of when your house is occupied and when it’s empty. The Lyric app monitors your current location and can transmit that information to the Lyric. In theory, this means that if you’re headed home, it can turn on the heater—and if you leave to go to the movies, it knows you’re gone and can immediately go into power-saving mode.
Not every member of a home owns a smartphone, and the act of setting up everyone’s phone with the Lyric app seems a bit much. I’m also not sure if this approach is much more than a gimmick—can’t the occupancy sensor do most of this work itself? And if the thermostat adjusts only when you come within a few miles of home, are the extra few minutes of heating or cooling really going to make much difference?
(A $5 third-party iOS app called Skylark adds similar geofencing capability to the Nest, and apps like Coming Home offer it for Android users. So if you’re intrigued by the Lyric’s geofencing feature, there’s a way to get it on the Nest as well.)
Though you can set the Lyric into Away mode by tapping its Away button, Honeywell seems to want you to control it mostly from its smartphone app. You can use the app to design different heating and cooling modes, which can be executed based on time or your location, or manually by tapping in the app. Setting up the modes seemed a bit too fiddly to me, and I found myself missing the simplicity of the Nest’s scheduling.
CNET’s Megan Wollerton gave the Lyric 3.5 stars, saying “a few performance and usability quirks make it hard to recommend today.” John Brandon at TechHive gave it just 2.5 stars (or hives, or whatever they are).
Like the Ecobee3, Lyric does have the advantage of supporting HomeKit. If you’re interested in the larger smart-home ecosystem and think you’ll swing toward Apple, it’s worth considering.
The $250 Honeywell Wi-Fi Smart Thermostat is a network-enabled smart thermostat, complete with a learning algorithm. Its features are arguably more impressive than Honeywell’s Lyric, but it’s a plastic rectangle with a touchscreen housing an old-school interface.
The $300 Honeywell Wi-Fi Smart Thermostat with Voice Control is pretty much the same product, but with the addition of voice-command capabilities, so you can shout across the room to make it cooler. This is probably the most impressive of the more traditional smart thermostats, and it’s Consumer Reports’s top choice.
The $450 American Standard AccuLink AZone950 was also a Consumer Reports top choice and is available through dealers. It’s yet another traditional rectangle with a touchscreen interface. It uses American Standard’s AccuLink Communicating System, so it’s really designed to fit into a house outfitted with American Standard equipment.
Another Consumer Reports top pick, the $550 Trane ComfortLink II xL950, is almost identical to the American Standard in look, features, and concept: It’s available via dealers and largely designed to fit in with Trane’s equipment. (Both American Standard and Trane are owned by the same parent company, Ingersoll Rand.)
Wrapping it up
Despite its age, the second-generation Nest is still the best smart thermostat for most people. The hardware is excellent, and the software behind it is elegant and smart. And the Works with Nest program means the Nest can integrate with a growing number of smart-home devices. However, Nest is in danger of losing its once-substantial lead in this category. The Honeywell Lyric isn’t as beautiful or as clever as the Nest—its focus on geofencing via smartphone app seems a little misguided—but it’s a solid device with (as CNET put it in its review) “a ton of potential.” The Ecobee3 is a scrappy upstart that essentially puts a smartphone app on your wall. It, too, has a lot of potential—but the software and smartphone apps need to be better.
Thermostat Ratings, Consumer Reports
A thermostat that learns? Three months with the Nest, Ars Technica, August 2, 2012,
This round thermostat has a few rough edges, CNET, July 3, 2014,
Ecobee’s new Ecobee3 closes in on Honeywell and Nest, CNET, September 30, 2014,
Ecobee3 Smart Thermostat - A Solid Nest Challenger, Zatz Not Funny, November 22, 2014,
This smart thermostat needs to wise up, PCWorld, December 4, 2014,
Originally published: February 12, 2015