Best Smart Thermostats of 2018

John Carlsen ·
Updated
We maintain strict editorial integrity when we evaluate products and services; however, Top Ten Reviews may earn money when you click on links.

Since 2016, we've tested 14 programmable thermostats to highlight those with the best features and ease of use. We recommend the Nest Learning Thermostat as our best overall pick. It analyzes your habits over time and collects other environmental data so it can adapt to your schedule and save you money. This thermostat is easy to install, and it is compatible with countless smart home products – it connects with more smart devices than any other thermostat we tested. 

Best Overall

Nest Learning Thermostat (3rd Generation)

The Nest Learning Thermostat is easy to use, has automatic scheduling to save on energy bills and is compatible with a wide array of smart home devices.
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Best Value

Emerson Sensi

The Emerson Sensi may not have automatic scheduling, but its three-year warranty, easy installation, Alexa voice controls and low price make it the best value among smart thermostats.
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Best for Voice Control

ecobee4

The ecobee4 holds its own against the Nest Learning Thermostat in almost every way and even has a few extra tricks, such as built-in Alexa voice controls and a remote sensor.
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Product
Price
$184.29Amazon
$200.00Amazon
$149.00Amazon
$155.99Amazon
$89.00Amazon
$79.34Amazon
$129.00Amazon
$135.00Amazon
$128.92Amazon
$165.00Amazon
Overall Rating
9.9
9.8
9.8
9
8.8
8.7
8.3
8.2
7.8
7.3
Temperature Control
9.9
9.9
9.9
9.7
9.7
10
9.9
10
9.8
9.9
Energy Management
10
10
10
8.3
8.4
8.7
5.3
5.9
4.7
2.5
Design & Setup
9.9
9.6
9.5
8.4
7.8
6.8
8.1
7.2
6.9
7.9
Warranty & Support
9.5
10
10
9
9.5
8.5
9.5
9.5
10
7.5
Geofencing
Via IFTTT
N/A
N/A
Auto-Schedule
N/A
N/A
N/A
Savings Feedback
N/A
N/A
Temperature Swing
+/- 1° F
+/- 0.9° F
+/- 1° F
+/- 1° F
+/- 1° F
+/- 0.5° F
+/- 1° F
+/- 0.5° F
+/- 0.25° F
+/- 1° F
Keypad Lock
Heating Stages
3
4
4
2
2
3
4
4
2
4
Cooling Stages
2
2
2
2
2
2
2
2
2
2
Ease of Installation
100%
95%
94%
75%
63%
68%
91%
82%
74%
86%
Common Wire Not Required
*
*
N/A
N/A
N/A
N/A
N/A
Interactive Compatibility Check
N/A
N/A
N/A
N/A
N/A
Built-in Level
N/A
N/A
N/A
N/A
N/A
IFTTT Integration
N/A
N/A
N/A
N/A
N/A
Home Automation Platform
Nest; Alexa; Google Home; SmartThings, Wink
Alexa; HomeKit; SmartThings; Wink
Alexa; HomeKit; SmartThings; Wink
Alexa; Wink; Google Home
Alexa; HomeKit; Google Home
ZigBee; Z-Wave
Alexa; HomeKit; Wink
Alexa; Wink
Alexa
Alexa
Usability
97%
97%
95%
88%
80%
75%
83%
74%
75%
91%
Motion Sensor
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Humidity Sensor
N/A
N/A
$
Weather Conditions
In-App
N/A
N/A
Warranty
2 Years
3 Years
3 Years
1 Year
2 Years
1 Year
3 Years
3 Years*
3 Years
1 Year
Support Channels
Social, Phone, Email, Chat
Social, Phone, Email, Chat
Social, Phone, Email, Chat
Social, Phone, Email, Chat
Social, Phone, Email, Chat
Social, Phone, Email
Social, Phone, Email
Social, Phone, Email
Social, Phone, Email, Chat
Email
Best Overall

Nest Learning Thermostat (3rd Generation)

The Nest Learning Thermostat saves energy by studying your preferences for a week. It monitors light and movement around it and observes when you change the temperature or schedule.
It also tracks weather near your home and gives you monthly progress reports to help save more energy. We like that Nest works with hundreds of smart home products such as Amazon Alexa and August Smart Lock. In fact, it works with more smart home products than other thermostats we compared. You can easily control the Nest using its metal outer ring and a mobile app. The app is user-friendly, lets you change settings quickly and has detailed tutorials to help you install the unit in your home. In our tests, it took around 17 minutes to install the Nest Learning Thermostat, which was the shortest installation of any product we tested. This thermostat also comes with a screwdriver, making it slightly easier to install than ecobee4, our runner-up. The Nest has a built-in battery that sometimes needs to charge after installation. Nest covers this product with a two-year warranty, which is average for most thermostats. (The longest warranty in our reviewed products is three years.) This thermostat costs around $250, making it one of the most expensive products in this category, though we believe the Nest is well worth the cost. The company also makes a cheaper model, the Nest Thermostat E, which offers many of the same features but supports less heating, ventilation and air conditioning equipment, and doesn't have as many design options.
Pros
  • Best smart home compatibility in our review
  • Excellent automatic scheduling
  • Easiest thermostat to install
Cons
  • Warranty is two years instead of three
  • Sometimes need to charge battery after installation
  • One of the most expensive smart thermostats
$234.85Amazon
Best Value

Emerson Sensi

The Emerson Sensi keeps things simple by leaving out some energy-management tools that make Nest and ecobee such excellent options, such as automatic scheduling and motion sensors.
While this is a disadvantage in some ways, it makes the Sensi more affordable than each company's top products; it costs about half as much as the Nest Learning Thermostat and the ecobee4. That said, the Sensi has many useful features, such as seven-day scheduling, weather information and geofencing. It also works with two of the most popular smart home platforms, Amazon Alexa and Apple HomeKit, both of which let you change the temperature with a simple voice command. We like that the Sensi mobile app is easy to use, with clear controls, though you can't look at usage data to see how much energy you're saving. While the Emerson Sensi lacks the sleek, modern appearance of Nest and ecobee, it's still quite attractive with its crisp interface. This thermostat is easier to install than most thermostats we tested – only Nest and ecobee were easier to install. To further add to the Sensi's value, Emerson covers it with a three-warranty, which is the longest warranty we've seen on smart thermostats.
Pros
  • Costs half as much as Nest and ecobee4
  • Easy to install and use
  • Three-year warranty
Cons
  • No auto-scheduling
  • No motion sensor
  • Not as sleek as Nest and ecobee
$141.99Amazon
Best for Voice Control

ecobee4

ecobee4 has two unique features among the thermostats we tested: It's the only model with built-in Amazon Alexa voice controls and it's the only one that includes a remote sensor in the box.
Amazon's Alexa service lets you adjust the temperature with a quick command, without using the ecobee app or touchscreen. We like the remote sensor because it lets the ecobee4 track temperatures in rooms other than where the thermostat is installed. Like Nest, ecobee4 has automatic scheduling features and monthly reports that look at your usage patterns, though there's a little more setup involved whereas Nest's is more automatic. Setting up this schedule isn't difficult, and it has most of the same features as Nest. One of the best qualities of ecobee4 is that its onscreen display and mobile app have identical controls, which makes it intuitive and easy to use. You can add ecobee4 to a number a of smart home systems, though it doesn't work with as many systems as Nest. Our installation tests went smoothly because the ecobee mobile app shows every step and guides the entire process. However, the Nest thermostat is marginally easier to install because it includes the tools you need. The ecobee4's three-year warranty is the longest we've seen among smart thermostats, and is one year longer than Nest's. The ecobee4 ranks among the most expensive thermostats we looked at, though ecobee makes a cheaper model, the ecobee3 lite, without built-in voice controls or an included remote sensor.
Pros
  • Built-in Alexa voice controls
  • Excellent user interface
  • Remote sensors
Cons
  • Slightly more difficult to install than Nest
  • Scheduling is not fully automated
  • One of the most expensive smart thermostats
$242.00Amazon

Why Trust Us  

We ultimately decide on our rankings based on our experiences during testing and the results each thermostat yielded, but we also did exhaustive research on consumer ratings at top online retailers and our competitors’ sites to track problems we might have otherwise missed. In total, we compared our results with 17 retailers and competitors to gauge each thermostat's potential.

We set three guidelines while choosing thermostats to test: First, they had to connect to a Wi-Fi network, and by extension, use a smartphone app. Second, they had to be available at retail stores and installable without professional help. Third, they had to connect to at least one other smart home product.

We tested 10 thermostats last year (2016), but for practical reasons, we didn't test each one for very long – only about an hour per thermostat to assess features and usability. This is in addition to the many untracked hours we spent researching thermostats since we first started reviewing them in 2012.

In our most recent round of testing, we looked at only three new models, so we kept each one installed for a day. To keep our results consistent, we used the same methodology this year as we did last year..

How We Tested 

Ease of Installation

Installation comprised a large part of our testing because we wanted to confirm that it was truly a DIY project. On average, it took about 30 minutes to install each thermostat. We found that thermostats with video tutorials, online compatibility checkers and built-in levels are the easiest to install.

DIY installation isn't difficult when you have a C wire and your pre-existing wiring is long enough to reach the terminals on your new thermostat.

Common Wire (C Wire)
A missing C wire adds some time to the installation process, but it's vital for powering features like Wi-Fi and always-on displays, as well as for extending battery life. The simplest solution is to choose a thermostat that doesn't need one, like the Nest Learning Thermostat or the Emerson Sensi. However, some thermostats, such as those by ecobee, have an adaptor kit that adds a C wire to your system.

Short Wiring
If your wiring's not long enough, you should replace the wiring with a longer strand, though it can be tough if you haven't fished wire through a wall before. It's best to pay an electrician to do it for you. While they’re at it, have them add a C wire if you need one.

Usability 

After installing each thermostat, we downloaded its mobile app to study the available features and determine how intuitive they are to use. In addition to our testing, we researched each thermostat to get a better picture of its long-term performance and overall customer satisfaction.

Each smartphone app can control basic functions, such as setting temperatures and schedules. However, the most impressive apps have the same user interface as the thermostat itself – this is one of the best things about the ecobee4, ecobee3 lite and Carrier Cor, since it makes using the features easy and intuitive.

Since many thermostats’ automatic features work largely on their own, we didn't extensively test them in the mobile apps, but we observed each thermostat's behavior while it was active to see how it performed.

What to Expect from the Best Thermostats

Before we continue, we should point out there's a small difference between programmable thermostats and their smart peers. Programmable thermostats rely on a schedule you set, with or without a smartphone app. Smart thermostats collect data about your home to make it easier to set schedules, or even eliminate the need for you to program a schedule. Here's what you can expect from the best thermostats:

Lower Utility Bills
Instead of setting a single, stable temperature as on a traditional thermostat, you can use a programmable thermostat to set a schedule for your home’s temperature at different times of the day. This saves money in both the short and long term by heating or cooling only when it's necessary. All programmable thermostats have schedules, but smart ones make the process of setting them easier in the following ways:

Auto-Scheduling

A smart thermostat builds on your schedule by adapting when your plans change. Some, like the Nest Learning Thermostat, auto-schedule by tracking your habits over time to learn your routines. Eventually, they may pick up on your schedule and preferences so well that you don’t need to adjust them at all. Other smart thermostats don't try to predict your schedule and instead respond to your activities.

Smart thermostats with auto-scheduling create a foundation for their programming by observing your habits and local weather patterns or by asking you simple questions. This works best when a thermostat has at least one of the following:

Usage reports
let you know how much energy you use and give feedback on how you can save even more. The best smart thermostats keep a record of your energy use starting the moment you activate them. Some thermostats have icons, like the Nest Leaf, to let you know you're improving.

Motion sensors allow the thermostat to react to events outside of your regular schedule, such as if you come home from work early one day. This is an advantage if you don't interact with your thermostat very often. Unlike schedules and geofencing, however, motion sensors can't make your home comfortable before you arrive home.

Geofencing creates a zone around your house and tracks your smartphone's location to activate home or away modes. While it is a useful feature, geofencing isn't as reliable as a schedule or motion sensors. As location services improve on smartphones, this feature will become more useful.

Smart Home Integration
Some Wi-Fi thermostat manufacturers include home automation functionality so their products can link to popular smart home devices. For example, a smart lock can activate your thermostat’s away mode when you lock the door, a security camera can record a video clip when someone adjusts the temperature, and a fitness tracker can adjust the heat while you sleep. If you have a smart home system, make sure the thermostat you want works with it before you make your purchase.

Smartphone App
Using a smartphone app, you can control your system remotely, view usage data and set schedules. All are useful in case you forget to set an energy-friendly temperature until well after you've left the house.

Rebates
Find out if your utility company offers rebates before you buy a new thermostat, since some offer incentives for you to install a programmable one, which can help pay for the upgrade. Your utility company wants you to conserve as much energy as possible, since that allows them to put what you save to use elsewhere.

A Long Service Life

Although new smart thermostat models come out every year, you don't need to replace them often. You can expect most units to last 10 to 20 years under normal conditions. We suggest you replace your smart thermostat when it breaks, when you upgrade HVAC equipment or if the mobile app stops working when a company goes out of business.


Decoding Common Thermostat Features

Temperature Swing
Temperature swing is how many degrees above or below the set temperature your home needs to reach before the thermostat activates your HVAC system. Models with narrow temperature swings of less than a half a degree keep your home the most comfortable, but run your HVAC system more often, which can wear down equipment and increase your energy bill. A wider swing is more efficient because it allows the temperature to vary more before activating your home’s heater or air conditioner.

Multistage Heating & Cooling
The thermostat can activate heating and cooling incrementally instead of just turning the system on or off. If one stage isn't powerful enough to adequately cool or heat your home, a stronger stage activates to reach the desired temperature. By using higher blower speeds only when necessary, the system saves energy.

Weather Conditions

Knowing the weather conditions near your home can help you save energy. For example, you can use this information on especially hot days to set the air conditioner warmer than normal or turn down the heat on mild winter days. Some thermostats, like the Nest Learning Thermostat, gather this data and use it in tandem with auto-scheduling.

Programmable Fans
The thermostat can run your air conditioner's fan to circulate the air in your home, which helps eliminate uncomfortable hot and cold spots. Some thermostats can also run the fan briefly after the compressor turns off, which uses leftover cold air in your system that would normally go to waste.

Remote Sensors
One of the latest industry trends is a thermostat with remote sensors you can place in different rooms of the house. These sensors track motion and temperature so your system can tailor its activity based on the room you're in, rather than an unoccupied hallway, which is where most homes have their thermostat.

For now, ecobee is the only company that makes remote sensors for its digital thermostats, which gives the ecobee4 and ecobee3 lite distinct advantages in larger homes. While many other manufacturers make thermostats that support remote sensors of some kind, this functionality is mainly available if you use a smart home hub and the sensors it's compatible with.

Maintenance Reminders
These reminders tell you when to perform basic maintenance, like replacing air filters. Some thermostats can also send you an alert when there's a problem with your HVAC equipment.

Warranty
The best programmable thermostats come with warranties of two or three years. However, some manufacturers provide a longer warranty if you have a professional do the installation. For example, the Carrier Cor has a five-year warranty if it’s professionally installed, but only a three-year warranty if you install it yourself.

Support
The best wireless thermostats come with complete customer service, including support reps who can be reached over social media, email, phone and live chat. Because social media support requests are so public, they add a layer of accountability that private communications, such as phone calls, emails and chats, often don't. For example, Twitter is one of the most effective ways to get help with your thermostat because responses are quick and often direct you to the most effective solution.

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