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 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 smart thermostat. Perhaps the most famous is Nest, snapped up by Google and dominating the space since 2013. But more traditional rivals including Hive and Honeywell have also managed to grab sizeable pieces of the action. There's also contenders like Ecobee, which is quickly gaining clout and backing.

Read on for a detailed brief of everything you need to know about smart thermostats, and how to choose your perfect system. Then scroll down for our in-depth reviews of the latest and greatest smart thermostats on sale now.

If you don't have time for all that – here's a snapshot of our current top picks…

Smart thermostats 2019 top picks

Nest Learning Thermostat
Nest Learning Thermostat

Ecobee SmartThermostat
Ecobee SmartThermostat

Honeywell Lyric T5/T6
Honeywell Lyric T5/T6

Nest Thermostat E
Nest Thermostat E

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, which is 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.

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.

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.

Get up to speed: Smart home ecosystems explained

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.

Read on for our pick of the best smart thermostat systems, tested at length in our homes and apartments.

The best smart thermostats for your home

Nest Thermostat

$249, Amazon |

The third-generation Nest Thermostat's biggest boast is that it learns and can create a schedule for you based on your heating behaviour, while at the same time encouraging you to stay within certain temperature zones for optimal heating – saving you money and helping to 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. And this headline feature actually works.

It does this by mimicking your manual actions based on its first few days of learning, and this auto-created schedule adjusts every time you make tweaks going forward. 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

With Nest, you're always encouraged to stay in the Leaf zone – an eco mode whereby you are using your energy most efficiently. In fact, you'll be emailed a monthly report telling you how well you've performed (how many leaves you've earned) compared to other Nesters in your area. So, shame on you if you whack the heating up to 23 on a nippy September's afternoon.

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).

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. All of this is set within the Nest smart home app – there's no specific Nest Thermostat app so it's not the easiest to just open up and change temperatures if you have cameras, doorbells, security systems and smoke detectors also installed (although there are third-party options).

However, the Nest Thermostat is very smart home friendly, even with the demise of the Works with Nest platform, you can control it using Google Assistant and Amazon Alexa, there's loads of IFTTT goodies already drawn up, plus it's part of the Friends of Hue club too. No HomeKit action though, which is a bummer.

The 229ppi display can be customised to show a range of Farsight faces – think weather, time and the like – and this, along with the range of steel and copper finishes, makes the Nest one of the best looking thermostats available.

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 prioritise some over others.

the ambient verdict
Nest Thermostat
A fantastic option, especially if you're looking to dive deeper into the smart home world as Nest plays nicely with a wide range of other connected kit. If you just want to plug a thermostat in and never think about heating again (well, after a few days' usage) then this is your best bet. It looks the part too, with its slick display and mini info apps.
  • Learning – so less manual input
  • Good smart home integrations
  • Hot water & cooling options too
  • No zone support
  • Quite expensive
  • No HomeKit option

The best smart thermostats for your home

Ecobee SmartThermostat

$249, Amazon |

Nest may be the biggest name in smart thermostats, but with its latest offering Ecobee proves it thoroughly deserves to share the spotlight. The little Canadian company has grown quite a bit since it was founded way back in 2007. The Ecobee SmartThermostat is its new flagship thermostat, and boy does it have features

The most unique of which is built-in Alexa, which has been upgraded since the Ecobee4 to make Alexa louder and clearer, thanks to an improved speaker. 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 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.

That said, the whole experience is less automated than Nest's, and we found ourselves reverting to manual controls most of the time due to Ecobee's sluggish response times. We also wish the user interface was a bit better – in the app and on the diminutive display itself – however, that's something that would be less of a concern if responsiveness was better. These problems aside, the Ecobee SmartThermostat still packs more features than Nest, and recent improvements to the built-in Alexa now makes it feel more like a proper Echo for your wall, rather than a hobbled third-party speaker.

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 ambient verdict
Ecobee SmartThermostat
The Ecobee SmartThermostat is an excellent device. Its souped-up internal specs mean you don’t need to worry about it becoming defunct in a few years, plus its responsive touchscreen makes it much more usable than its predecessors. It requires more vigilance than a Nest to get maximum energy savings and comfort, but its multiple control methods, excellent smart home integrations, and multipurpose sensors are all best in class.
  • Great smart home integrations
  • Fantastic room sensors
  • Built-in Alexa improved
  • Responsive touchscreen
  • No native geofencing with iOS
  • App and UI are overly complex
  • Home/Away not responsive enough
  • Expensive

The best smart thermostats for your home

Hive Active Heating

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

Hive is developed by Centrica, one of the world's biggest energy companies, and started in the UK, capitalising on the position of trust British Gas has within UK households. But Hive has branched out – it’s now available in the US, and offers a bit more than heating (or cooling) control. We’ve been testing the service for a couple of years, and have been impressed with its progress.

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.

Read this: The complete guide to the Hive smart home

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 jury is out on design of the thermostat unit. Hive signed up tech design guru Yves Béhar to style it with reflective glass and customisable frames. Many might prefer a small discreet white box, others like the more stylish Hive unit.

The app is pretty easy to use, well-suited to those who have reservations about teching-up their heating. The user starts at a honeycomb of all their Hive connected devices, which will show the current temperature and whether heating is on at-a-glance. Neat additions include the one-hour heat boost mode, which is designed to mimic the button found on older boiler systems.

But Hive is still missing features such as localised 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.

Hive is more than just a heating system, though. Unlike Tado, Honeywell, and to a lesser degree Nest, the Hive ecosystem now boasts smart plugs, bulbs, door sensors and home security cameras. They’re all easy-to-use and reliable, and make for a vibrant smart home setup.

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. In the UK you can buy the thermostat for a one-off price with fitting, or join the US with a monthly, two-year subscription that includes access to extra software features such as the ability for your lights to mimic your normal behaviours while you're away from home.

the ambient verdict
Hive Active Heating
The smart thermostat that aims to keep things simple, Hive is a great connected heating system. Techier users will miss some of the smarter AI learning features and items like connected radiator valves, but the system itself gets the basics right, with little extras like the one-hour heating boost being a nice touch. What's more, Hive's ecosystem of bulbs, plugs, and cameras make expanding your smart home simple.
  • Set up by an engineer
  • Simple app
  • One hour heating boost
  • Decent wider ecosystem
  • Fine tuning less easy
  • No radiator valves
  • Fewer AI features
  • Alexa only

The best smart thermostats for your home

Nest Thermostat E

$169, Amazon |

Now available in both the US and the UK, the Thermostat E is Nest's 'budget' option and, while it does sacrifice a few of the stand-out features that make its more-expensive brother one of our top picks, there's still a lot to get excited about with the E.

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 polarised, glass display giving it a nice frosted finish. 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.

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.

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.

Apart from the Link E and the table stand, the E for the UK is basically the same device it is in the US. You can still control it from the Nest app or via Google Assistant – but there's no Alexa support just yet.

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 there's also no option to control the hot water on the E.

the ambient verdict
Nest E
The Thermostat E is a nice looking smart thermostat that actually trumps its pricier stablemate in terms of versatility and temperature sensing. It does lack some of the features of the Learning but still does a fantastic job of the basics of a smart thermostat, while at the same time not breaking the bank.
  • Easy to install
  • Portable form factor
  • Low price
  • Farsight feature is missing
  • Low-res display
  • No Alexa support in UK

The best smart thermostats for your home

Tado Smart Thermostat

$149.99, Amazon |

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.

Read this: Tado co-founder talks future thermostat features

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.

the ambient verdict
Tado Smart Thermostat
While the set-up for Tado requires a lot more effort on your part, once working it offers superb control of your home heating and is fairly agnostic when it comes to voice assistant platforms. The radiator valves mean you can quickly set up zones around your home, although the geo-location needs a bit more attention.
  • Use any voice assistant
  • Clean, easy app
  • Radiator valves for easy zones
  • Geo-location a bit fiddly
  • Set-up far from simple
  • Basic design

The best smart thermostats for your home

Honeywell Lyric T6

From $179, Amazon |

The Honeywell Lyric T6 isn't the most comprehensive Honeywell connected heating controller – that honour belongs to the 12-zone, all-singing, all-dancing Evohome. And it's not the best looking either – the circular Lyric Round takes that prize. But what the T6 does offer is plenty of bang for its buck and a wealth of evolved features from one of the (if not 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, which can be moved around the house (i.e. it's 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 centred 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 Optimised 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. However, 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 the app 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 controls for changing the temperature.

the ambient verdict
Honeywell Lyric T6
The Lyric T6 is just one of many Honeywell smart thermostats on offer but for simplicity, value, and features, it's a top pick. The geofencing is particularly strong and the back-to-basics scheduling makes heating your house a breeze. Sure, it's missing a trick or two (hot water support being one) but pound-for-pound, the T6 is a great option. Don't bother with the extra cash for the T6R – if you want control around the house just use the app.
  • Great value for money
  • Excellent geofencing settings
  • Smart assistant intergrations
  • Geo and scheduling issues
  • Slightly bulky looking
  • The T6R isn't completely wireless

Glas Thermostat

The best smart thermostats for your home

$319, Amazon |

Out of the box, Glas has two things going for it: it’s the best-looking smart thermostat available today, and it was designed by Johnson Controls, the company who invented the room thermostat 135 years ago, so you can feel confident this is made by people who know what they're doing.

Other features that stand out from the crowd are air-quality monitoring (both indoor and outdoor), Cortana built-in (a plus if Microsoft’s virtual voice assistant is your AI of choice – if not it also works with Alexa or Google Assistant speakers), and a hefty price tag (at $319 it’s the most expensive consumer-grade smart thermostat).

Beyond that, the smarts in this US-only thermostat are centred around an occupancy sensor in the device. If it senses you’re home a pre-set ‘home’ temperature range kicks in; if it detects you’re away then ‘away’ temps are in charge to save energy (and money). It also knows when you are sleeping (because you tell it your bedtime during setup) and sets to sleep temperatures during those times. You can change any of the preset temperature ranges at any point.

Occupancy sensing is at the heart of most smart thermostats, but most others do it better. Nest uses other Nest devices and your phone’s location, Ecobee has its remote sensors, and Honeywell uses geofencing. Glas relies entirely on you walking past the thermostat. You can turn off occupancy sensing if you don’t walk past your thermostat much, but then you just have an expensive programable thermostat.

Programming Glas also isn’t intuitive. You can manually add “away” times to the schedule it creates during setup (in the app or on the device), but you can only use the pre-set Home/Away temperature ranges, you can’t set specific temp setpoints. Of course, you can change the temperature using the device, app or voice control at any point, but it won’t adapt its schedule based on those changes, meaning you’ll need to keep adjusting it manually.

Glas’ best feature is its screen. The 5-inch OLED, touchscreen display is super responsive, easy to read and simple to navigate, and you can control Glas entirely from this Windows IOT Core-powered screen (a good thing as the app is slow and buggy). It also looks gorgeous, lighting up colourfully when you’re in front of it, though of course with a screen this big to power it requires a c-wire (but comes with an adaptor). The downside is, if you’re replacing an existing thermostat then the clear design leaves you looking at ugly holes in the wall, unless you do some serious patching or use the included backplate, which completely kills the design aesthetic.

The indoor/outdoor air quality monitoring is a nice feature and negates the need to buy a separate IAQ monitor if you’re concerned about air quality. However, Glas just shows you the data – it won’t automatically turn the fan on if say VOCs or CO2 levels are too high; you have to turn it on manually or set it to run automatically for a few minutes every hour.

If you have a reliable schedule, a central location to put a thermostat, and you really like the look of Glas this is a good option. Integration with Cortana, Alexa, and Google Home means you have lots of smart home capabilities available to you, and the occupancy sensor should save you money if you never programmed your old thermostat. But Glas is not the smartest smart thermostat money can buy.

the ambient verdict
Glas Thermostat
A flashy thermostat that boasts serious style and some basic smarts, this is one for Microsoft fanboys and design devotees with plenty of extra cash. As a smart thermostat it’s lacking a killer feature, although the indoor air quality monitoring is a nice touch. Integration with three out of four voice assistants is also a plus, and it has the best interface amongst the increasingly crowded competition.
  • Attractive design
  • Responsive touchscreen
  • Monitors air quality
  • Senses occupancy
  • Expensive
  • Slow, buggy app
  • Occupancy sensing is unreliable
  • Scheduling is limited

TAGGED    thermostats    smart home    buyers guides

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