Owning a smart thermostat is an important step to completing your smart home - not only will it simplify your life by intelligently warming and cooling you home, but it will save you money in the long run, too.
The best smart thermostats learn your routines, like when you leave the house in the morning and when you go to sleep at night. You can control them from anywhere in the world through your phone, enable you to adjust temperatures room-by-room, and even let you control your heating using your voice.
As with most technology, there are a wide range of smart thermostats, and different models each have their own particular selling points. In this guide, we've broken down the best smart thermostats you can buy from the biggest names in the business: Nest, Hive, Honeywell and Tado.
For each smart thermostat, we'll explain their key selling points, and which particular environment each one is best suited to: You may value price over smarts, or want a smart thermostat that looks like a piece of art, rather than something utilitarian.
Because of the nature of the market, a direct comparison isn't actually very helpful, so the units here aren't ranked by number according to our preference. Instead, we recommend each one of these smart thermostats – they're all great. It's up to you to decide which one is best for your needs and home.
Nest Learning Thermostat
The smartest kid in the class
Dimensions: diameter: 84mm, height: 31mm | Screen: 24-bit color LCD, 480 x 480 resolution | Sensors: 10 temperature sensors, indoor humidity, proximity, near-field activity, far-field activity, ambient light | Zonal control: no | Connectivity: Wi-Fi, Wireless Interconnect, Bluetooth Low Energy
Nest is one of the biggest names in the smart home market, and for good reason. This Google-owned company delivers well-designed, easy-to-use products that are packed with serious smarts.
The Nest Learning Thermostat (third generation) is renowned for its ability to learn your routines and adjust itself accordingly. This means that over time your heating system can actually adapt to suit your needs, without you having to do anything.
It also benefits from location-based features that track where your phone is, and will turn the heating on or off depending on your location. But don't worry that it's going to turn off the heating and leave your guests to freeze when you're out, as its built-in sensors enable it to detect whether there's anyone at home.
The main criticisms of the Nest Learning Thermostat are that it doesn't offer zonal control, and that if you're a tech novice it can be a little complicated to set up and use. The absence of zonal control means that while you'll be able to digitally control your property as a whole, you'll still have to manually adjust individual radiators.
That said, if you're looking for a top-of-the range system Nest is a good way to go. Plus, with Google behind it, Nest is a good system to invest in if you're planning to build a wider smart home setup.
- Read the full review: Nest Learning Thermostat 3rd generation
Hive Active Heating 2
A stunning little thermostat with the smarts to match
Dimensions: 100 x 100 x 48mm | Screen: 3.5-inch color TFT display, 320 x 480 resolution | Sensors: Temperature | Zonal control: with Active Heating Multizone | Connectivity: Zigbee HA 2.0
Hive is owned by Centrica, one of the UK's leading energy providers, so you can rest assured that you're in experienced hands when it comes to your heating needs. While the company may be British, Hive products have been available in the US since 2017.
The thermostat itself is a collaboration between Hive and Swiss designer Yves Béhar, who's responsible for everything from the August smart lock to PayPal's brand identity. That top-quality styling makes the Hive Active Heating thermostat something you'll be proud to have on your wall.
What's more, Hive has an excellent ecosystem, so you're able to control a vast range of Hive products using a single app. And its thermostat is no slouch, garnering our 'recommended' tag thanks to its simple interface and easy voice assistant integration.
It's worth noting that, like the Nest thermostat above, Hive Active Heating doesn't support Apple's HomeKit, so it's best avoided if you're already invested in Apple's smart home ecosystem.
With a small dial in the middle of its compact design controlling temperature, the Hive Active thermostat gives you the option of keeping things extremely simple, while being packed with features for those who want greater control of their system.
- Read the full review: Hive Active Heating 2
Honeywell Evohome
The easiest zonal control available
Dimensions: 139 x 101 x 21mm | Screen: 24-bit color LCD, 480 x 272 resolution | Sensors: temperature sensor | Zonal control: yes | Connectivity: Wi-Fi, Bluetooth
The Honeywell Evohome gives you total control over your home, with individual thermostats for each radiator enabling you to set an independent heating schedule for every room in your house.
It's difficult to grasp what a difference this feature makes until you've tried it for yourself. If you live in a house where different inhabitants prefer a different temperature, or if one room always seems to be hotter or colder than the others, this system is going to be a godsend.
What's more, it works with under-floor heating too, so even if you have a large and complicated heating system the Evohome gives you total control over all of it via an app that's a pleasure to use.
The control panel and radiator thermostats aren't going to win any awards for design, coming as they do in plain white plastic, but that's not really the point of the Evohome. It's a simple system, without the bells and whistles of the Nest or Hive, but if you've got a complicated heating system that you want to control digitally, it's hard to beat.
- Read the full review: Honeywell Evohome
Tado Smart Thermostat
The best looking zonal control on the market
Dimensions: diameter: 104 × 104 × 19mm | Screen: LED matrix | Sensors: temperature sensors, indoor humidity, ambient light | Zonal control: yes | Connectivity: via Tado Internet Bridge connected to router using ethernet port
The Tado Smart Thermostat should be brilliant. It offers the zonal control of the Honeywell Evohome, a slick design that rivals the Hive, and the geofencing smarts to match the Nest, but somehow it doesn't quite manage to pull all these features together into a cohesive system.
It's seriously good-looking – by far the most attractive zonal control on the market – but the app is unintuitive to navigate, and compared to the incredibly user-friendly app on the Evohome, it's positively difficult.
That's not to say it's a bad system – it's still comfortably a 4-star product, and we don't imagine anyone who buys the Tado regretting their purchase. And it's so close to being the perfect system – the one that mixes together the best features of other offerings. The problem is, it just doesn't manage to outshine any of its rivals.
One thing that does make the Tado stand out in this list is Apple HomeKit integration – if you're the proud owner of a HomePod, or you're firmly entrenched in the Apple ecosystem, this is probably the best smart thermostat for you.
It's also worth noting that the things keeping Tado from standing out are all software rather than hardware issues, so these could well be addressed over time. The Tado Smart Thermostat isn't currently available in the US, but as Tado's Cooling system is sold there we'd be surprised if it didn't become available at some point.
- Read the full review: Tado Smart Thermostat
Nest Thermostat E
Nest smarts, on a budget
Dimensions: diameter: 81mm, height: 29mm | Screen: 24-bit color LCD, 480 x 480 resolution | Sensors: temperature, humidity, proximity, ambient light | Zonal control: no | Connectivity: Wi-Fi, Bluetooth Low Energy
If you like the look of the Nest Learning Thermostat but don't fancy shelling out the money for it, there's a cheaper alternative. It definitely looks cheaper – it's made of white plastic, with a white coating on the plastic screen that can make it hard to see the information being displayed – but it does echo the design language of the original Nest Thermostat, so you'll be more than happy to have it on your wall.
As the Nest's smaller sibling it benefits from industry-leading smarts, lacking only the most advanced features of the premium model which most users are unlikely to take advantage of anyway.
The Nest E is a great example of how to streamline a flagship product to make a cheap alternative without damaging the qualities that made the original great. Make no mistake, this isn't flagship quality for bargain price, but it's great value for what it is.
- Read the full review: Nest Thermostat E
Ecobee4 Smart Thermostat
(US Only) Probably the smartest thermostat on the market
Dimensions: diameter: 109mm, depth: 26mm | Screen: 3.5” full-color LCD touch screen, 320 x 480 pixel display | Sensors: temperature, humidity, proximity, ambient light | Zonal control: no | Connectivity: Wi-Fi, Bluetooth Low Energy
If it's available where you live, the Ecobee4 is well-worth auditioning for your smart home setup. Like other smart thermostats on our list, you can control the Ecobee4 using a smart speaker or smart hub – but, unlike any of the other entries, the Ecobee4 comes with Alexa built right in.
That means, not only is it a great thermostat that can save you bundles on your energy bill each month but it doubles as a conduit to Alexa and its 10,000-strong library of skills. Besides being able to order pizza (yes, really) the Ecobee4 can be controlled wherever you are in the world – should, say, you forgot to turn that thermostat off before your international flight.
While Ecobee may not have the same clout that Nest has garnered in the last few years, it remains one of the best thermostats on the market, bar none.
Ecobee3 Lite Smart Thermostat
(US Only) Save some green by keeping Alexa out of the thermostat
Dimensions: diameter: 109mm, depth: 26mm | Screen: 3.5” full-color LCD touch screen, 320 x 480 pixel display | Sensors: temperature, humidity, proximity, ambient light | Zonal control: no | Connectivity: Wi-Fi, Bluetooth Low Energy
OK, so not everyone needs another device with Alexa built-in. (We get it, guys, you can build Alexa into anything!) If you're in the camp of people with too many Alexa devices, the Ecobee3 Lite is the perfect solution - it's just the smart thermostat without the smart assistant.
Now, that said, the Ecobee3 is still compatible with all the leading smart home ecosystems. (Ecobee was the first smart thermostat compatible with Alexa, believe it or not.) But if you want the all the extras, like room sensors that can detect temperatures in certain spots in your home, you'll have to buy them separately.
- Now you've got the best thermostat, check out our Best security camera round-up