Are Smart Thermostats Worth It?

Smart thermostats that meet Energy Star criteria save users an average of 8 percent on their utility bills, according to data gathered by the Environmental Protection Agency. What that means in dollars and cents depends on where you live and other factors, but with electricity rates rising steeply across much of the country, the annual savings can be substantial.

The secret to the energy savings is pretty simple: Smart thermostats turn down the heat and AC more often than regular thermostats, without sacrificing comfort.

Some smart thermostats do this is by figuring out when nobody is home, most commonly with motion or occupancy sensors, or by checking the location of your phone (aka geo-fencing). When the thermostat senses that your house is empty, it’ll switch to an energy-saving model.

Most internet-connected thermostats don’t have that ability. But any smart thermostat can make it easy to set up a sensible heating and cooling schedule. You can use an app to program the thermostat to adjust heating and cooling for when you’re asleep, away at work, or traveling on vacation.

Regular programmable thermostats (without WiFi or smartphone apps) have been able to do this for decades, but their buttons and touchscreens tend to be cumbersome. And 29 percent of programmable thermostat owners don’t take advantage of those features, according to a nationally representative survey of 2,015 U.S. adults conducted by Consumer Reports in February 2025. The app-based interfaces for smart thermostats are much easier to use. 

At the high end of the category, Google Nest popularized the concept of “learning” thermostats, which try to automatically set a heating and cooling schedule based on when you tend to be home and how you use the thermostat over time. But the feature seems to have waned in popularity. Many thermostat makers have moved away from it, with Google Nest even making it optional. For more information on the pros and cons of learning thermostats, see our guide to Google Nest thermostats.

Smart thermostats often integrate a few additional strategies and features, including reports on how often your system runs or messages about how choosing milder temperatures can save energy. Many models also remind you to replace your HVAC filter (usually every three months). Finally, many smart thermostats can connect to demand response programs that allow your utility company to adjust the thermostat settings during times of high demand (such as a summer heat wave) in exchange for financial incentives.

Even if you don’t use an app to set up a schedule, a smart thermostat can let you adjust the heat or AC if you forget to do it manually before leaving on a long trip or when you’re returning home.

Some smart thermostats work with remote temperature sensors to help you get the right temperatures in the right rooms at the right time. If your main thermostat is on the first floor but you spend most of your day working in a second-floor home office that runs warm, you can pop a remote sensor on your desk so that the AC kicks in as needed—before you sweat through your shirt. These sensors can’t fix all the problems of an unbalanced HVAC system, and could actually increase your energy bills by running the system more often, but it’s an option to consider.

And the simple ability to turn on your HVAC system from your smartphone can be a boon for comfort, too. If you’re coming back from a long trip and the thermostat has been turned way down, you can set it to your normal temperature from the tarmac or the interstate an hour or two before you get home.

Some people might find that a simpler thermostat suits their needs better than a higher-end model with automation, sensors, and other smart features. People who understand and appreciate how smart thermostats work—essentially letting their house get warmer or colder sometimes—tend to be satisfied with them, according to Bryan Orr, founder and owner of HVACRSchool.com and president of Kalos Services in Clermont, Fla. “But if the client doesn’t understand it, then they don’t tend to value it,” he says. He also says that even some of his nerdier clients still sometimes find themselves puzzled by the behaviors of learning algorithms on higher-end smart thermostats.

In some homes, a smart thermostat simply won’t do much to save energy or improve comfort, especially if you’ve already harvested all the low-hanging fruit of energy conservation.

For example, if you already have a “regular” programmable thermostat with scheduled heating and cooling periods, a smart thermostat may not save much additional energy.

Homes that are occupied most of the time, say, if you work from home, will see smaller savings because there will be fewer opportunities for the energy-conserving modes to kick in when the house is empty.

In temperate climates, where energy use and utility bills are naturally lower, a smart thermostat will save less money than average, and certainly less than in places with very hot summers and frigid winters, particularly if they also have high energy costs. It should still trim your costs by about 8 percent on average, but that’s 8 percent of a relatively low number in the first place. 

Modern variable-speed air conditioners, and especially heat pumps, are designed to work better and more efficiently when they run constantly at a fixed temperature. So a smart thermostat’s big energy-saving tool—turning off the system periodically—can actually work against that goal. (A simple smart thermostat that doesn’t automatically change your settings could still make sense, though.)

Finally, if you have an older HVAC system without a C-wire (basically a dedicated power line for your thermostat), you’ll need to select a smart thermostat carefully. Many models won’t work without one. C-wire adapters are sometimes available, but they don’t always work well. And even if a smart thermostat can work without a dedicated C-wire, it won’t always work with very basic two-wire, heat-only systems. In our ratings, we indicate which smart thermostats will work with these legacy setups.

Electric baseboard radiators generally won’t work with most smart thermostats, either, because the voltage levels are mismatched. There are exceptions, though CR hasn’t tested them.

Below are the best smart thermostats from our ratings. See CR’s thermostat ratings for full results on all of the models we test.