The Best Smart Thermostats

This is the thermostat that pays attention to more than one room. Every thermostat reads the temperature where it's mounted, which is usually a hallway nobody uses. The included SmartSensor reads a room you care about and tells the system somebody's in there, so the furnace runs for the bedroom instead of the wall by the front door. If your office over the garage is always the wrong temperature, that's the fix.

Ecobee rates the savings at up to 26% a year on heating and cooling, measured against holding a house at a flat 72 degrees. Treat that as a ceiling rather than a promise. It's ENERGY STAR certified, which matters mostly because it makes the unit eligible for utility rebates in a lot of territories, and those are worth checking before you order.

The built-in air quality monitor flags when the air in your house goes bad, suggests what to do about it, and nags you when the furnace filter is due. Owners are split on how much they use it. Several say the filter reminders alone earn their keep, while others report the air readings end up being interesting rather than actionable, and they'd have been fine with a simpler ecobee.

The security half of the bundle is the part to think hardest about. You get two door and window sensors, a radar motion sensor that covers the main floor when you're out, and a thermostat that listens for the sound of a smoke alarm. It's genuinely useful, but the sharper alerts, including motion notifications when the system is armed, depend on an ecobee Smart Security subscription.

It talks to everything. There's a speaker and microphone on board for hands-free Alexa, and it works with Siri and Google Home as well, which makes it the safest choice if the phones in your house don't all agree. Ecobee also ships a power extender kit, so a home without a C wire behind the faceplate can still run it without pulling new wire.

Flaws but not dealbreakers

It's the most expensive setup here, and a chunk of that cost is security hardware you may not want. If all you're after is a thermostat that handles rooms well, you're paying for sensors that will sit in a drawer.

The door and window sensors are where the install goes sideways. Owners describe long setup sessions, at least one dead sensor out of the box, and a support call to sort it out. The thermostat itself goes on the wall quickly; budget extra patience for the extras.

It's a physically large unit. On an older wall cutout you may see the ghost of the previous thermostat around the edges, which means paint or a trim plate.

The screen is the reason people buy this one. It's about 60% larger than the previous generation, and Dynamic Farsight lights it up with a clock, the weather or the temperature when you walk past, so it reads from across the room. Brightness adjusts on its own, or you can set it yourself. Owners consistently call out how well it disappears into a hallway.

Its best trick is that you never have to build a schedule. It watches what you do for a week or two and starts anticipating the changes you'd have made anyway. When it wants to alter your schedule to save energy, it asks first, sends the proposal to the Google Home app, and waits for you to tap yes. That's a real improvement over older Nests that just decided things.

It comes with a Nest Temperature Sensor, so you can point comfort at one room at a certain hour, like the nursery at bedtime. It's less flexible than ecobee's occupancy-aware approach, since you're telling it where to care rather than letting it notice. But for the classic problem of one cold bedroom, it works, and you can add more sensors later.

Compatibility is broad on paper: most 24V systems, including gas, electric, oil, forced air, heat pumps and radiant, with no C wire needed in most homes. It's Matter compatible, which makes it easier to fold into a mixed smart home. Run your wiring through Google's compatibility checker anyway, because the exceptions are the expensive kind of surprise.

Flaws but not dealbreakers

The no-C-wire claim doesn't hold for everyone. Owners report cases where a third-generation Nest ran fine on the same wiring and this one wouldn't, partly because the mounting and power hardware changed between generations. If your current thermostat is a hand-me-down setup, check before you commit.

Apple households get less than they'd like. Siri control runs through a smart speaker rather than a native Apple Home integration, so the automations you can build are thinner than with the ecobee. And full functionality assumes a Google account you're comfortable feeding.

The energy reports are pretty but coarse. If you want to know exactly when your system ran and why, ecobee's dashboard tells you more.

No other thermostat here scales across a house like this one does. The wireless Smart Room Sensors reach up to 200 feet, so a sensor in an upstairs bedroom still reports cleanly to a thermostat on the ground floor. One comes in the box and you add the rest as you go. For a two-story home where the top floor bakes in July, that's the whole ballgame.

The sensors read temperature and detect people, and you choose how the thermostat uses that. It can follow whoever's home and prioritize whatever room they're in, or stick to a schedule that shifts priority room by room through the day. Owners who sleep upstairs describe it in the simplest terms: they stopped conditioning the hallway and started conditioning the bedroom.

The hardware is straightforward and the color touchscreen is easy to read without your phone, which is more useful than it sounds when a guest or a kid wants to change the temperature. It works with Amazon Alexa, Google Assistant and Apple HomeKit, so it's the rare non-ecobee option here that Apple-first households can actually automate.

Check the system list before you buy. It handles forced air on gas, oil or electric, hot water and steam, and heat pumps with electric backup. It does not work with electric baseboard heat, and it requires a C wire, though a C-wire adapter is included for homes that don't have one.

Flaws but not dealbreakers

The app is the weak spot. Owner complaints about the Resideo app and its smart home integrations stretch back years, and while updates have helped, this isn't the one to buy if you plan to live inside the phone interface.

Extra sensors are sold separately, so a large deployment adds up quickly. The switch between averaging across rooms and following a schedule also confuses people; more than one owner has reported settings appearing to revert overnight until they worked out which mode was in charge.

Energy reporting is basic next to ecobee's, and the design is functional rather than handsome. Nobody's putting this one in the entryway to be admired.