The best smart thermostats for your home

Buyers guide: Our reviews of the leading thermostats

The best smart thermostats
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The first port of call for many smart home users is a connected thermostat – and for good reason. Getting better control of your home's heating isn’t just a huge win for convenience. You can save a lot of money by heating your home more efficiently, and there’s no better feeling than popping the heating on during your commute and arriving home to a warm house.

There are plenty of options for those looking for a top smart thermostat. Perhaps the most famous is Nest, which has been dominating the space since 2013 and has now been fully subsumed by Google. But more traditional rivals including Hive and Honeywell have also managed to grab sizable pieces of the action, while contenders such as Ecobee has quickly gained clout.

Read on for our list of the best smart thermostats available, followed by a detailed brief of everything you need to know about choosing your perfect system.

The best smart thermostats for your home

Best smart thermostat: Ecobee SmartThermostat

Buy now: Amazon, | $249

Nest may be the biggest name in smart thermostats, but with its latest offering Ecobee proves it thoroughly deserves to share the spotlight. In fact, with its latest SmartThermostat, we think Ecobee has finally become the new reigning champion.

The Ecobee SmartThermostat is its new flagship thermostat, and its most unique feature is built-in Alexa. It's the Amazon Echo of the thermostat world. Yes, the Ecobee4 had it too, but thanks to an improved speaker it's now louder and clearer. There's a little LED light at the top of the Ecobee that produces Alexa's iconic bluish-green hue. And, well, Alexa behaves just like Alexa here – obeying your voice commands and answering questions – but it can also control the thermostat itself.

Even better, the Ecobee SmartThermostat is compatible with all the major platforms: HomeKit, SmartThings, Google Assistant, IFTTT. If you're building a smart home, rest assured this will fit right in.

The Ecobee comes with a bunch of smart scheduling features, including some that make use of the external sensors and your smartphone to tell when someone's arriving home, where in the house they are, and adjust accordingly. It can manage the temperature of a home in such a way that it'll concentrate its efforts in rooms that are occupied, and leave rooms that aren't. There's one room sensor packaged with the thermostat, but you can purchase more separately for other rooms.

Ecobee is compatible with most residential heating and cooling systems in North America, but not high-voltage systems. Setup is easy if you already have a C-wire installed – it took us about 15 minutes – otherwise you can make use of the bundled power extender kit, but this is more complicated and best installed by a professional.

The all new Ecobee smart security platform also means that an Ecobee can now play its part in your overall smart home setup too.

What we love

  • Excellent smart home integrations
  • Fantastic room sensors
  • Built-in Alexa improved
  • Responsive touchscreen

What we don't love

  • No native geofencing with iOS
  • App and UI are overly complex
  • Home/Away not responsive enough
  • Expensive

Read our full Ecobee SmartThermostat review.

The best smart thermostats for your home

Runner-up: Nest Learning Thermostat

Buy now: Amazon, | $249

The third-generation Nest Thermostat's biggest boast is that it learns your behaviors to create a schedule for you, while at the same time encouraging you to stay within certain temperature zones for optimal heating; it will save you money and help you reduce wasted energy.

When you manually use the Nest, rather than relying on a schedule, it can start to form a pattern based on when you like certain temperatures – for both when you're at home and away. Of course, you can also choose your own schedules, and there's a neat True Radiant mode that learns how long your home takes to hit a certain temperature so adjusts its start times based on that.

Key differences explained: Nest Learning Thermostat v Nest Thermostat E

Unlike Tado, Nest had no zone options or individual radiator control – although it is possible to use third-party smart radiator valves alongside Nest, with the thermostat simply acting as a maximum temperature controller (as a dumb thermostat would, with connected valves).

There's also the US-only $39 Nest Temperature Sensor. You can place it on a shelf or wall and it'll track the temperature in a certain room, which is important because not all rooms and hallways in your home are the same temperature. This basically allows you to properly heat or cool certain rooms, and prioritize some over others.

Nest's Home / Away mode is particularly strong, especially if you use other Nest products that can detect your whereabouts, such as Nest Protect or any Nest Cams. There are also neat features that cross Nest devices, such as turning off your system if a Protect detects carbon monoxide.

Nest is also now testing a new thermostat feature to help identify potential issues with your heating, ventilation and air conditioning (HVAC) systems. If a potential issue is detected, they will send you an email alert.
For example, your Nest thermostat may notice that it's taking longer than normal to cool your home, therefore there might be a problem with your cooling system.

What we love

  • Learning – so less manual input
  • Good smart home integrations
  • Hot water & cooling options too

What we don't love

  • No zone support
  • Quite expensive
  • No HomeKit option

The best smart thermostats for your home

Best for a budget: Nest Thermostat E

Buy now:Amazon, | $169,

The Thermostat E is Nest's "budget" option and, while it does sacrifice a few of the extra features that make its more expensive brother one of our top picks, most of the core stuff is still here.

A far cry from the metallic, shiny, high-end Nest, the E's white plastic looks help it blend into the background more, with a polarized, glass display giving it a nice frosted finish. Like the Nest the E detects when you're home or away and sets the temperature accordingly, and also has the ability to set schedules so that it knows what it needs to do at all times.

One big omission is Farsight, and it's not compatible with as many HVAC systems as the Learning model (about 85% compared to Learning's 95%). There's a compatibility checker on the website so you can see if it supports your system.

That frosty display is also a clever way of hiding the fact that it comes with a lower resolution panel than the Nest, although it's still perfectly easy to read the current and target temperatures.

If you live in the UK you don't have to hang the E on your wall either, as it comes with a stand, making it easy to place it on a table or a shelf. This makes it portable too, meaning you can get a more accurate measurement of the heat in a particular room at any given time – as with the Lyric T6.

The UK version of the E comes with the Heat Link E, a fabric disk that replaces your existing thermostat using the same wiring. Installation is simple with Nest walking you through how to replace your old thermostat with the Link E.

What we love

  • Easy install
  • Portable form factor
  • Great price

What we don't love

  • No Farsight feature
  • Plasticky design

Read our full Nest Thermostat E review.

The best smart thermostats for your home

Runner-up budget choice: Hive Active Heating

Buy now: Amazon | $179.99/ £249 (with Hub) in UK, £199 (no Hub)

The Hive thermostat itself is best suited to less technical users in smaller homes. First off, it’s battery powered, so you don’t need to wire it in. That’s a biggie – and the controller will last around six months on a set of four AAs.

Key features include the ability to remotely turn heating on and off and set up schedules based on room temperature, which is more than most boilers offer. There’s also holiday mode, which stops heating your home until you return, but stops short of automating based on your smartphone’s location like Nest.

The app is pretty easy to use, well-suited to those who have reservations about teching-up their heating. Neat additions include the one-hour heat boost mode, which is designed to mimic the button found on older boiler systems.

Read this: The complete guide to the Hive smart home

But Hive is still missing features such as localized radiator controls, which means it’s not as powerful as rival platforms from Honeywell or Tado. It does boast multi-zone heating, but that means installing more thermostats. Again, that’s okay for an upstairs/downstairs setup, but not so good for four individual bedrooms, plus the east and west wing of your mansion beach house.

Of course, the need to keep your smart home within the Hive family is negated by platforms like Alexa, Apple HomeKit and Google Home. Alexa support is a big part of Hive and works well, but support is yet to roll out for anything else. Hive does have its Home Hub 360 to control the whole system.

But it’s the kind of system that’s perfect for non-techie users, doesn’t pull punches when it comes to the ecosystem, and best of all, you get a trustworthy engineer to come and fit it.

What we love

  • Set up by an engineer
  • Simple app
  • One hour heating boost
  • Decent wider ecosystem

What we don't love

  • Fine tuning less easy
  • No radiator valves
  • Fewer AI features
  • Alexa only

New best thermostats xxxxx

Best for larger homes: Honeywell Home T9 Smart Thermostat

Buy now: Amazon | $199.99

Honeywell's T9 might lack some of the flash of its competitors, but there are still plenty of reasons to get it. Chiefly, it has the best range of sensors, which can track humidity, temperature and presence.

The sensors also work with geo-fencing, so you can have your Home, Away, and Sleep apply to specific rooms. Sensors were really responsive in testing, and we loved being able to use Alexa and Google Assistant to target them individually; there's just no HomeKit support yet, but we're promised it's coming.

It's just a shame those sensors are so unsightly, but at least the thermostat itself isn't bad, just a little bland. The touchscreen display works a treat though, showing you the time, current indoor temp and outdoor temp.

The T9 supports up to 20 sensors, and if you wish yo can tell your system to average the temperature out across them all so the whole home is comfortable, or target just one. It can even prioritize rooms where motion is happening – handy!

We also really love the adaptive recovery feature, which will heat or cool your home a little bit sooner than you ask it to, meaning it will reach the desired optimums at the right times.

What we love

  • Sensors detect motion and humidity
  • Responsive touchscreen display
  • Simple, unobtrusive design
  • Well-designed app

What we don't love

  • Either geofence or schedule
  • No motion sensor in the thermostat
  • No energy reporting
  • No HomeKit yet

Read our full Honeywell Home T9 Smart Thermostat review.

The best smart thermostats for your home

Best for compatibility: Tado Smart Thermostat

Buy now: Amazon, | $149.99,

A lesser known system out of Germany, Tado treads the line between a system aimed at those who want the maximum features from their smart thermostat, and something fairly stylish that won’t look out of place in your home.

The diminutive white box acts as the thermostat, but the main work is done on your smartphone. The app enables you to set the temperature remotely and set up schedules for your home. But things quickly take a techier edge.

While geo-location is available on Nest and Hive, it’s put front and centre on Tado. As you head home, Tado will start to warm your house, upping that level the closer you get to home. It’s not a foolproof system; it works well in general, but falls down if you intend to spend the entire day local to your home, as you’ll have to manually intervene. You can use a sliding scale to manage the aggressiveness of the geo-location, or just turn it off.

Unlike Nest and Hive, Tado offers individual radiator thermostats, which will enable you to quickly add zones to your home. It’s a cheap and quick way to make your heating system a lot more powerful – but again will add a level of complexity you have to be willing to manage.

You will also have to deal with a setup that’s a lot more labour intensive than the Hive. A bunch of pre-registering was required before an engineer could be summoned and we had to deal with Tado support to verify our brand new boiler was compatible, which took a week. The engineer who came to install the system wasn’t able to explain the app or how it worked – and inexplicably couldn't or wouldn't fit our radiator valves. Again, not an issue for confident users, but we wouldn’t advise it for anyone who’s not especially smart home savvy.

But the pay-off is a wealth of smart compatibility. Try Alexa, Google Assistant, and Apple HomeKit control for size – only Ecobee offers the same level of ubiquity across systems, which essentially future-proofs control of your setup.

What we love

  • Use any voice assistant
  • Clean, easy app
  • Radiator valves for easy zones

What we don't love

  • Geo-location a bit fiddly
  • Set-up far from simple
  • Basic design

Read our comprehensive Tado verdict

The best smart thermostats for your home

Best for the basics: Honeywell Lyric T6

Buy now: Amazon, | From $179

The Honeywell Lyric T6 isn't the most comprehensive Honeywell connected heating controller – that honor belongs to the 12-zone, all-singing, all-dancing Evohome. But what the T6 does offer is plenty of bang for its buck and a wealth of evolved features from one of the biggest names in the smart thermostat game.

There are actually two versions of Honeywell's latest smart thermostat – the regular T6 and the T6R – and both can be moved around the house (i.e. not wall mounted). It does mean a bit more flexibility with the slightly-more-expensive T6R but, as with all thermostats, you really should have it placed in a room that best tells the story of your home's average temperature.

Like the Tado, a lot of the best features with the Lyric T6 are centered around geo-location, using your smartphone to check your location and see whether your heating should be on or off. The manual geofencing area function within the Lyric app is great, allowing you to determine your own Away and Home locations. After all, a mile from home might mean a long walk or a quick two minutes on the bus.

Like Nest and Tado, the Lyric T6 is 'intelligent' and will start heating in time to get to what it thinks will be your desired temperature at the correct time (using the Optimized Start function), meaning you won't suddenly find yourself feeling cold and, more importantly, saving you money by not wasting energy. There's no learning with the Lyric though; everything is based on what you tell it to do – based on your Home, Away or Sleep status.

Scheduling is great within the app, although annoyingly you can't (easily at least) have both the geofencing and scheduling options running concurrently.

The Lyric app is about the simplest we've come across, with a big wheel representing a temperature controller and big clear buttons for jumping in and out of the various settings. However, we did find it somewhat flaky during our testing, with the system being disassociated from a user account on more than one occasion. Any problems we did have were on Android, though – on iOS it was seamless.

The Lyric T6 was the first connected thermostat to launch in the UK with HomeKit support and the device gets along fine with Alexa and Google Assistant too – and there's a wealth of IFTTT recipes out there as well, if you want more than voice commands for changing the temperature.

What we love

  • Great value for money
  • Excellent geofencing settings
  • Smart assistant intergrations

What we don't love

  • Geo and scheduling issues
  • Slightly bulky looking
  • The T6R isn't completely wireless

What does a smart thermostat do?

The key feature of any smart thermostat is giving you remote control of your heating, anywhere in the world, via your smartphone. But there’s a bit more on offer than that.

Many traditional heating systems require an ugly, plastic thermostat in your house, and some don't have any thermostatic control whatsoever, meaning users put on the heating when they’re cold, make the house too hot, and turn it off again. It's a huge waste. You can set up timer control, and inevitably forget to turn it off when you’re away, and heat the house unnecessarily.

This is where smart thermostats prove their worth.

First, they work thermostatically, letting you set an optimum temperature for your home, which should save you a wedge of cash. You can then create proper schedules, remotely turn the heating on and off, and ensure it's shut off properly when you go away on holiday.

Some also come with optional sensors that can be placed around the home to target the temperature in specific rooms – but you can still reap many benefits if you don't have the external sensors.

While tech companies like Nest really kickstarted this trend, established HVAC systems have now caught up, afraid of being left behind; you can now find smart thermostats from the likes of Honeywell and Bosch.

What to consider when buying a smart thermostat

The smart home is a quickly evolving place and thermostats are just one piece of the puzzle. You may want to control lighting, heating, security, and a host of devices within your home. So a key consideration is how you can ensure your stuff will work together.

Before you do anything, you need to understand how your current system is wired. The good news is that most smart thermostats are compatible with at least two-stage heating and cooling systems, but pay more attention to the specifics is your system is larger than that.

Get up to speed: Smart home ecosystems explained

The bad news is that not all will work with all of your other equipment such as heat pumps and ventilation systems. So consider what you have in your home and whether a smart thermostat is going to really benefit you.

It’s also worth considering the control afforded by your setup. A simpler system will offer whole home control, while others will let you get as granular as controlling the temperature in every individual room (if you buy the relevant sensors and controllers). Some are more hands-on and some learn your weekly habits or use geofencing to try to make the whole experience as hands-off as possible.

Apple users will want to look at HomeKit integrations, while others will want to ensure that you can control your thermostat via Amazon Alexa or Google Assistant. If you have to control your lights via your smartphone but your heating and cooling using a different app – well, that’s going to get irritating.

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