The Best Smart Thermostats to Conserve Home Energy and Cut Costs On Electricity Bills

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If you’re a thrifty homeowner, you’re probably already layering up during winter so you don’t have to crank the heat—and then in summer, you wait until it gets really hot before you switch on the air conditioning. Investing in a smart thermostat is another tool in your arsenal to help you conserve energy and save money on your electricity bill.

A smart thermostat is the most convenient way to remotely control your home’s temperature and ensure the heating or air conditioning aren't blasting when you’re not even home to feel it. After all, according to Energy Star, 42 percent of the average annual electric bill in the U.S. is dedicated just to heating and cooling. With a smart thermostat, you could save hundreds by scaling back your a/c without boiling this summer, and more during the milder days of winter, when that heat isn't needed.

The Best Smart Thermostats

What to Consider

What’s the Ideal Home Temperature?

There’s no one-size-fits-all answer to what temperature you should set your thermostat. Direct Energy suggests that you can save money and stay comfortable in the winter by keeping your home between 68 to 72 degrees, while summer settings may be better between 73 to 78 degrees.

However, you can save even more by using a programmable thermostat that adjusts the temperature when you’re out of the house or sleeping. For example, according to the U.S. Department of Energy, you can save up to 10 percent on heating and cooling just by turning your thermostat 7 to 10 degrees higher or lower for eight hours a day from your preferred normal setting. If you’re still working from home for most of the day, even just a 1-degree reduction in temperature overnight can reduce your energy bill by 1 percent.

Wiring

One of the most common problems in wiring a smart thermostat, says Porzio, is that the home’s heating-cooling control circuit has only four wires, and lacks a fifth wire known as a common. The common (also called the C wire) provides constant low-voltage power to the thermostat. Lack of the all-important fifth wire in the circuit wiring causes many homeowners to stumble through the installation.

Porzio says that typical damage from miswiring may be a burned-out transformer (the device that converts the home’s 120 volts to the low-voltage necessary to operate the heating-cooling system) or a burned-out fuse on the low-voltage control circuit in the furnace or air handler. A fuse is a protective device that will melt if it receives too much current, opening the circuit and preventing current flow. Once a homeowner damages a heating-cooling system by miswiring the thermostat, it’s time to call a contractor.

“My advice on any thermostat would be first to make sure you understand the wiring,” says Porzio. “Watching a YouTube video does not suffice! Second, use a thermostat from a manufacturer that is dedicated to HVAC controls, such as Aprilaire, Ecobee, or Honeywell.”

Types of Thermostats

While smart thermostats may cost more upfront, their remote and smart capabilities will allow you to save the most energy and money in the long run. All of these smart thermostats install in your home easily if you have a common (or C) wire, but some may require professional installation if you aren’t confident in basic electrical wiring. Because they use Wi-Fi, you may also want to ensure yours is close to the router, or get a Wi-Fi range extender to improve the connection.

While we recommend a smart thermostat, here are the differences between all the types you’ll likely encounter if you’re looking to upgrade yours.

How We Selected

We researched 10 expert sources, 66,000 consumer reviews, and tested a couple of options ourselves to select the best smart thermostats. To determine our Total Expert Score, we calculate the ratings from trusted publications such as CNET, Tech Radar, Digital Trends, and PC Mag, and convert them to a 100-point scale to make it easier for you to weigh the best options. Our Consumer Score represents the percentage of customers who rated the product at least four out of five stars on retail and review sites like Amazon, Walmart, Home Depot, Lowe’s, and Best Buy.

Don't lose your cool. Check out our picks for the best window air conditioners and best portable air conditioners.

BEST FOR ALEXA

Ecobee Smart Thermostat with Voice Control

We’ve tested the latest smart thermostat from Ecobee for several months, and it continues to impress. The good feelings started during installation when we called customer service at 10 p.m. on a Friday and got a simple answer to a wiring question in seconds. Once the thermostat was up and running, controlling it from the app was easy and intuitive.

It works with optional standalone sensors (one is included; additional units cost $79 for two) that monitor temperature and household activity to adjust the temp in the spaces you’re actually using. The free Eco+ software unlocks the potential for even more savings by adjusting your thermostat’s schedule and settings based on the electricity rates in your area.

Like with other smart thermostats, you can program temperatures, and the system learns your habits to improve efficiency. Over the course of our testing, we’ve seen electric and gas bills drop about 10 to 15 percent compared to when we were using our old standard thermostat. This new model has a sleek glass finish, which adds a little style to the unit, and the sensors have longer battery life than previous ones. The Smart also supports 5GHz Wi-Fi in addition to 2.4GHz, which makes it a good choice for anyone with dual-band routers.

What’s more, the fifth-generation Ecobee also functions as a speaker and comes with voice controls with built-in Amazon Alexa. Fortunately, Ecobee doesn’t lock you into the Amazon ecosystem, since the thermostat is also compatible with Google Home, Apple HomeKit, and other smart systems.

BEST FOR GOOGLE HOME USERS

Google Nest Learning Thermostat

Like the Ecobee above, Google’s Nest can learn your habits to reduce energy use while keeping your home comfortable. Though the Nest doesn’t include remote sensors, there’s still much we like about this unit. Its auto-scheduling is intuitive to set up, the dial design is pleasing to use, and installation is easy as long as you have a C wire. Even without additional motion sensors, the Nest will know when you’re home thanks to its geofencing feature that detects your smartphone. If you have issues with certain rooms in your home not maintaining the right temperature, you can purchase a Nest Temperature Sensor separately for $39, which works up to 50 feet away from the main thermostat to help make sure the room where the sensor is placed is the exact temperature you set.

It’s tight competition between Ecobee Smart and Nest, with the Nest Learning—which is just as simple to use with a great design—winning in the price department. Also like the latest Ecobee, the Nest has some premium features like Bluetooth support and dual-band Wi-Fi connectivity.

What’s different is a feature called “Farsight” that displays the time, temperature, or weather, so you can read it even across the room. Plus, this smart thermostat comes in a variety of finishes, so you can match it to your home’s style. While the Google Nest is also compatible with Alexa and other smart home systems, it may be a better choice for those who use other Google Home devices, since everything can then be controlled via the same app. Otherwise, the external sensors and voice control give the Ecobee a very slight edge over this one in terms of functionality.

MOST VERSATILE

Ecobee3 Lite Smart Thermostat

Though the Ecobee3 Lite doesn’t have an Alexa speaker built-in, it’s designed to be adaptable in terms of connectivity, working well with any other smart home setup. Despite its abundance of connectivity options, however, the Lite just isn’t as “smart” as some other thermostats. You can certainly purchase Ecobee’s room sensors separately to use with it, but it doesn’t have any included.

Unlike the most advanced Ecobee and Google Learning thermostat, the Ecobee3 Lite doesn’t have the smart tech that learns your schedule and adapts the temperature accordingly, so it mostly functions as a standard seven-day programmable thermostat—just with more smart home connectivity options to control it remotely. Like the higher-priced Ecobee, however, this basic version is still easy to install and comes with the same Eco+ software, plus has a similar design with its responsive 3.5-inch color touchscreen.

BEST BUDGET

Google Nest G4CVZ Thermostat

This Nest looks to be an improvement upon the old budget Nest Thermostat E. It’s an affordable option and doesn’t have the same advanced features as the Nest Learning. But it is programmable, so you can set a schedule for it to change temperatures—or use sensors and your phone’s location so it knows when you’re home or away. You can also control it from anywhere through the Google Home app, which has a handy Savings Finder feature to identify ways to help you preserve money and energy. Perhaps best of all, it’s sub-$100 with a stylish modern design in sand, charcoal, or snow color options.

FOR OLD-SCHOOL COOL

Honeywell Home RTH6580WF Thermostat

Sometimes simple is better. Honeywell’s RTH6580WF adds a dash of smart technology to the chunky monochromatic display of old-school thermostats. With large physical buttons that are easy to press, navigating the thermostat is a breeze for every member of the household.

Honeywell's app features a modern user interface and smart assistant controls that allow you to adjust temperatures, program events, and monitor the condition of your air filter from anywhere in the world. Without a touchscreen interface or fancy display technology driving up the price, the RTH6580WF also happens to serve as a great budget pick.

One unexpected feature is the auto-learning smart response function. Usually reserved for more higher-end thermostats, this allows the RTH6580WF to automatically adjust the temperature of your home based on your usage at certain times of the day.

BEST ENTRY-LEVEL

Honeywell Lyric T5+ Smart Thermostat

The Honeywell Lyric T5+ has basic smart features but also punches above its price point in some departments. While it has seven-day scheduling like most other cheap smart thermostats, it can also adjust your house’s temperature, based on whether you’re home or away, through geofencing—capability usually reserved for more expensive units. One Amazon reviewer even said that the geofencing feature worked better for their household than Nest’s Learning scheduling because they didn’t keep a regular schedule. The Lyric T5+ also sends your smartphone notifications to remind you to change air filters or warn you about extreme indoor temps.

Reviewers also said that installing this smart thermostat was easy if they already had a C wire. And the Lyric works with a variety of heating and cooling systems, though not humidifiers, dehumidifiers, and ventilators. Its design and display aren’t as attractive as the Ecobee’s or Nest’s, but it’s not an eyesore either. For those who don’t have complex heating and cooling needs, it’s got the best smart features on a budget.

FOR ELECTRIC BASEBOARDS

Mysa Smart Thermostat

If you don’t have a central HVAC system and instead rely on an electric baseboard or fan-forced system, this Mysa is an excellent thermostat to consider. It’ll integrate with any of your preferred smart home systems, including Amazon’s Alexa, Google Assistant, or Apple HomeKit. And it can use a combination of scheduling and geofencing to determine if you’re home, plus multiple users can operate it through the accompanying app (a good or bad thing, depending on how varied your temperature preferences are). While you may be stuck with that old electric baseboard, you can at least upgrade your thermostat to Mysa’s modern, minimalist design.

Installation is generally quick and easy to DIY, but keep in mind before you buy that installing the Mysa requires four or more wires (including a neutral 120-volt or second live 240-volt wire) and it’s only rated for electric heating systems up to 3,800 watts.

BEST VALUE

Emerson Sensi Smart Thermostat

Like the Honeywell Lyric T5+, Emerson’s Sensi includes features like seven-day scheduling and geofencing to automatically adjust the temperature. It’ll integrate with all of the most common smart home systems like Alexa, Google Assistant, and Apple HomeKit. And the large touchscreen works well, though it looks slightly outdated compared to the Nest and Ecobee budget models. The geofencing and other practical features of this smart thermostat don’t function significantly better than the Honeywell or other options under $200. But if you don’t want anything flashy and are looking for a decently priced thermostat, the Sensi is a safe bet.

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