The Best Smart Thermostats of 2019

Table of Contents

By reducing your energy usage, smart thermostats can pay for themselves, while making your heating and cool bills up to 23% less expensive. Of course, there are a number of factors going into which smart thermostat is right for your smart home, from HVAC compatibility to mobile app user experience and everything in between. With so many options floating around, what are the best smart thermostats in 2019?

In this review, I’m bringing you the cream of the crop from brands like Nest, ecobee, and Honeywell. I reviewed and tested each thermostat in terms of its design, features, installation process, and app before giving you my top picks. To learn more about how I made my decisions, see the ‘Methodology” section below. Otherwise, let’s get started!

Best Smart Thermostats

The Best Smart Thermostat for Multiple Zones
Nest Learning Thermostat
Nest Learning Thermostat
Nest Learning Thermostat

Paired with the Nest Temperature Sensors, the Nest Learning Thermostat can detect temperature, humidity, proximity, occupancy and ambient light in different rooms around your house. 

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The Best Smart Thermostat for Alexa
ecobee4
ecobee4
ecobee4

A smart thermostat and a smart home platform all in one, you'll love controlling your ecobee4 with Amazon Alexa, or, if you're in the Apple ecosystem, Apple HomeKit. 

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The Best Smart Thermostat for Google Home
ecobee3 lite
ecobee3 lite
ecobee3 lite

Not only does the ecobee3 lite work with Google Home, but it also works with Alexa, Apple HomeKit, Microsoft Cortana, Samsung SmartThings, IFTTT— the list goes on. 

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The Best Smart Thermostat for Heat Pump
Honeywell Home T9
Honeywell Home T9
Honeywell Home T9

Not only does the Honeywell Home T9 work with heat pumps, but it also has integrations with Amazon Alexa, Google Assistant, IFTTT, and more, making it a flexible option for your smart home. 

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The Best Smart Thermostat for Multiple Zones

Scheduling the Nest Learning Thermostat

Nest Learning Thermostat

If you want your thermostat to work in multiple zones, the Nest Learning Thermostat is by far the best option. You can use up to 20 Nest thermostats per home, with up to three homes allowed per account. Either put a thermostat in every room, or, for a more affordable option, use Nest Temperature Sensors. Sure, the Nest Learning Thermostat is definitely not the cheapest around at $249, but with an average savings of 10 to 15% on heating and cooling bills, your Nest Learning Thermostat and temperature sensors will pay for themselves, eventually. 

So what makes the Nest Learning Thermostat so great? ENERGY STAR-certified, this thermostat can sense humidity, proximity, occupancy, and even ambient light. That means that it detects not only motion, but also body heat, so it’ll know if you’re home and sleeping, in another room, or simply immobile. It’ll also know if no one is in the house and will adjust accordingly. Plus, you can connect it with your phone’s GPS so it automatically adjusts based on your location (a process called geofencing), or you can set it to schedules. Of course, it also works with Amazon Alexa and Google Assistant, making it easy to control with your voice alone. 

Please note that the Nest Learning Thermostat only works with low voltage, 24 volt systems. It’s also probably not the best choice if you’re an iPhone user, given the Nest app’s low rating on the Apple store. Otherwise, it’s a life-saver, particularly if you have a large home! 

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Nest Learning Thermostat
Nest Learning Thermostat
Nest Learning Thermostat

After a week of usage, the Nest Learning Thermostat will learn your schedule so you never have to worry about your home's temperature again. 

The Best Smart Thermostat for Alexa

Smart Platform Integrations on the ecobee4

ecobee4

Amazon Alexa is the most popular voice assistant, so if you’re looking to use her with your smart thermostat, I recommend the ecobee4. Not only can you command Alexa to adjust your thermostat, but the device will also function as a smart home hub, playing music, answering questions, and the like. And for those in the Apple ecosystems, you’re in luck: the ecobee4 also works with Apple HomeKit

Battery-powered, the ecobee4 has schedules, integrations with IFTTT and Samsung SmartThings, and humidity, proximity, and occupancy sensing. You can also set up geofencing so long as you have Android devices. The ecobee4 doesn’t require a c-wire to install and is compatible with oil, gas, electric, and dual fuel systems. At $195, it’s at an average price for smart thermostats, plus the ecobee app has awesome ratings on both the Google Play and Apple stores. In sum, there’s very little not to love about the ecobee4! 

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ecobee4 Smart Thermostat
ecobee4 Smart Thermostat
ecobee4 Smart Thermostat

With integrations with Amazon Alexa, Samsung SmartThings, Apple HomeKit, IFTTT, and more, there are tons of ways to command and automate your smart home with the ecobee4. 

The Best Smart Thermostat for Google Home

ecobee3 lite Thermostat. Photo provided by ecobee.

ecobee3 lite

If you’re in the Google smart home ecosystem, the ecobee3 lite is a fantastic choice. But it’s also a great choice if you have Amazon Alexa, Apple HomeKit, Microsoft Cortana, IFTTT, Samsung SmartThings, or Wink. In fact, the ecobee3 lite has some of the most smart platform integrations I’ve seen from a smart thermostat, which is extremely impressive. 

Hardwired into your home, the ecobee3 lite works with gas, oil, dual fuel, and electric systems, making it pretty flexible. You can control it via the above voice assistants, geofencing, or schedules. It’s also touchscreen and can sense humidity and proximity. Plus, at $169, the ecobee3 lite costs less than average when compared to other smart thermostats, which is never a bad thing. 

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ecobee3 lite Smart Thermostat
ecobee3 lite Smart Thermostat
ecobee3 lite Smart Thermostat

With humidity and proximity sensing and integrations with Apple HomeKit, Amazon Alexa, Google Assistant, and Microsoft Cortana, you'll love using the ecobee3 lite Smart Thermostat in your smart home. 

The Best Smart Thermostat for Heat Pump

Honeywell Home T9

If you have a heat pump and want your smart thermostat to be hardwired into your home, look no further than the Honeywell Home T9. It works with most 24 V systems, although it won’t work if your system is electric or millivolt. Of course, it’s ENERGY STAR-certified, meaning that the Environmental Protect Agency has deemed it to be energy-efficient. 

So just how does the Honeywell Home T9 save you energy? Well, it features geofencing, schedules, and tons of integrations with voice assistants, including Amazon Alexa, Google Assistant, and Microsoft Cortana (with an Apple HomeKit integration on the way). It also works with connected devices from Samsung SmartThings, and anything IFTTT-enabled, so you can fully automate your smart home.

At $199.99, the Honeywell Home T9 is at an average price for smart thermostats, plus, the Honeywell Home app has a 3.3 on the Google Play store and a 4.5 on the Apple store.  With humidity, occupancy, and proximity sensors, you’ll be able to see exactly how much you’re saving in a monthly energy report. 

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Honeywell Home T9 Smart Thermostat
Honeywell Home T9 Smart Thermostat
Honeywell Home T9 Smart Thermostat

Whether you're in the Amazon, Google, or Microsoft smart home ecosystems, the Honeywell Home T9 Smart Thermostat can work in your smart home. 

Smart Thermostat Pricing Rundown

As you can see, the Nest Learning Thermostat is the most expensive thermostat on the list, primarily because of its A.I capabilities. At only $169, the ecobee3 lite is the only thermostat that’s below market prices, while the ecobee4 and Honeywell Home T9 are at average prices. None of these require hubs or bridges, although you may want to buy temperature sensors to go along with some of them, if you have a large house. Also, keep in mind the following:

  • Nest thermostats can save you 10-12% on heating and 15% on cooling, according to an independent study
  • ecobee thermostats save people an average of 23% on their heating and cooling bills.

Honeywell also has a section on their website where you can calculate how much money their T9 will save you, so that’s something to keep in mind when you’re considering the cost. Sure, you might be spending a lot, but unlike most purchases, these products will all pay for themselves after a period of time.

Smart Thermostat Methodology

Smart Thermostat Methodology
Smart Thermostat Methodology

Just how did I come to my conclusions about the best smart thermostats of 2019? I’ll tell you!

Design

Design means a few things. Of course, aesthetics will probably play a part in your decision, so make sure that you like the way your thermostat looks. There are many different styles, finishes, and colors available, so make sure you find something that you won’t mind looking at. Thermostats tend to be no more than five inches wide, but there is also a bit of variance there.

But the main thing that you want to consider is compatibility. Different smart thermostats work with different HVAC systems, be them oil, electric, low-voltage, high-voltage, and more. You also want to figure out if the thermostat requires a c-wire or not, a wire in your home that connects thermostats to power. Fortunately, most thermostat websites provide simple compatibility checks on their websites, so definitely check that out before buying.

You can also choose between hardwiring your thermostat into your home or having it operated by battery. Again, this is a personal preference, as battery-powered thermostats are easier to install but require changing or charging the batteries periodically, and vice versa. You should also figure out the thermostat’s connectivity, which is usually Wi-Fi, Bluetooth, or both.

The majority of smart thermostats have full color, LCD screens which may or may not be touchscreens. If they’re not touchscreens, you’ll be able to adjust the outside ring like an old-school thermometer, which is equally as simple. While some companies place limits on the amount of thermostats you can have in your house, some are unlimited.

Finally, you want to make sure that the smart thermostat you choose is ENERGY STAR-certified. That means that the Environmental Protection Agency has reviewed it and has deemed it to be energy efficient. Make sure that your thermostat doesn’t use more than five kWh per month, and you’re in business!

Features

Now, there are a number of ways you can change your smart thermostat aside from on the actual device itself or the mobile app. All of the smart thermostats that I’ve reviewed also include geofencing and schedules. A little more about each:

Smart Thermostat Geofencing
Smart Thermostat Geofencing
  • Geofencing: Geofencing allows you to sync your thermostat with the GPS on your phone, so that your home can be a comfortable temperature when you’re there and an energy-saving temperature when you’re not! Now, I’ve seen some smart thermostats that only provide geofencing on specific devices like Androids, so make sure your cell phone is compatible.
Smart Thermostat Schedules
Smart Thermostat Schedules
  • Schedules: This one’s pretty self-explanatory; you can create schedules for your thermostats so that they automatically adjust throughout the day. Literally all of the smart thermostats I’ve reviewed have schedules, so this is a must.

The other way to control your smart thermostat is through voice commands, which brings me to my next point.

Smart Platform Integrations

If you’re thinking about investing in a smart thermostat, then you probably already have a smart home ecosystem set up, be it Amazon, Google, Apple, or Microsoft. Before you buy, make sure that your thermostat is compatible with the relevant voice assistant. All but one of the thermostats that I’ve reviewed work with both Amazon Alexa and Google Assistant, the two most popular, so this shouldn’t be too difficult to find.

Aside from smart home platforms themselves, many smart thermostats can be synced with other connected devices in your home from brands like LIFX, Wemo, Logitech, and more. That means you can have the devices’ actions trigger one another, like having your thermostat turn up to 70 degrees Fahrenheit when your security system is disarmed, meaning you’re home. If you already have tons of IoT devices, this is something you should definitely be thinking about as you’re making your buying decision.

Sensing Capabilities

Aside from temperature, smart thermostats can also sense humidity, proximity, occupancy, and even ambient light. Let me explain:

  • Humidity: Ah, the dreaded humidity. It can have a huge effect on how warm it feels, even if the temperature doesn’t technically change, so it’s good that all but one of the smart thermostats I’ve reviewed detects humidity.
  • Proximity: A fancy word for motion, most smart thermostats can tell if someone walks in front of them and can adjust their temperatures accordingly.
  • Occupancy: This one is slightly different from proximity, although it’s also used to tell if there are people home. Occupancy measures infrared body heat rather than motion, so it can tell if you’re home, home and asleep, or completely out of the house. Two-thirds of the smart thermostats I’ve reviewed can measure occupancy, and I think it’s a pretty essential feature.
  • Ambient light: Finally, the ability to sense ambient light allows thermostats’ screens to brighten or dim automatically, saving you even more energy. This feature is the least necessary and most rare of all the sensing capabilities.

Extras

All of the smart thermostats I’ve reviewed will provide you with an energy usage report so you can see exactly how much you’re saving. They all allow for multiple users so your friends and family can join in on the fun. But the only unique feature I’ve seen is the Nest Learning Thermostat’s ability to learn users’ schedules after a few days. Beyond that, all the features are now covered.

Installation

While hardwiring is more difficult in the short-run and more convenient in the long-run, battery-powered thermostats are the opposite; it’s totally up to you which one you choose. Again, make sure your thermostat is compatible with your HVAC system before you buy. I personally test out and install every thermostat I review to make sure the process isn’t too arduous, but you can always pay for professional installation, if you prefer. There’s no real way to know if your thermostat is going to be easy to install or not— but hey, that’s why you have me!

App

You’ll control your smart thermostat through its mobile app. It’s also where you’ll set up geofencing, smart platform integrations, and create schedules, if you prefer. Make sure the app has a rating above three stars on either the Google Play or the Apple store, depending on what kind of mobile device you have. And that’s it for apps!

Recap of the Best Smart Thermostats of 2019

So that’s it for the best smart thermostats of 2019! If you need a quick recap for my top picks, here you go.

  • The Best Smart Thermostat for Multiple Zones: Nest Learning Thermostat
  • The Best Smart Thermostat for Alexa: ecobee4
  • The Best Smart Thermostat for Google Home: ecobee3 lite
  • The Best Smart Thermostat for Heat Pump: Honeywell Home T9

Want to get a personalized recommendation? Leave a comment below! I hope to hear from you soon.

Gabe Turner

Gabe Turner

Gabe Turner is an attorney and journalist with a passion for home tech and secure, efficient living. Since graduating from NYU Law, he has maintained a paradoxical existence of trying to live life adventurously while remaining staunchly risk-averse. He is torn by the dual desires of wanting to only be in Brooklyn writing about housing policy and smart home tech and aspiring to visit his friends scattered across the globe. Gabe believes that stable, safe communities are the cornerstone to a vibrant and healthy society, and it is this passion that brought him to contribute to Security Baron.

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