Best smart thermostat 2018: save money yet stay warm

The best thermostats and smart radiator valves from Nest, Hive, Netatmo and more

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If there's one piece of smart home technology that will make a difference to your life, it's the smart thermostat.

Until recently, was there a more uninspiringly dull household item than the thermostat? All that ugly white cheap plastic and incomprehensible programming buttons.

Clearly a design revamp has been a long time coming, and as far as most punters are concerned, it arrived with the Nest Learning Thermostat and Hive from British Gas, and Germany's Tado. These are the best on offer, albeit with slightly diifering strengths

The app-accessible integrated heating system was now a reality, with – at least in theory – no more complicated programming interfaces, no more coming home to a freezing house with burst pipes, water all over the carpets and a massive repair bill, and no more waking up in a fridge when the temperature plummets.

How to buy the right smart thermostat for you

Most smart thermostats also work with a wider range smart home devices, allowing you to create some automated processes in your home.

Used cannily, most of the smart thermostats featured here should save enough in energy costs to pay for themselves within a year or two.

You can even get some units discounted through your energy provider – British Gas will install Hive for free (you still buy the unit, but there's no installation cost) and  Npower will flog you the Nest for just £159 if you're an existing customer. EDF Energy will also install the Netatmo for £199, although the product is currently unavailable.

Right now, our pals at AO are offering 20% off the full range of Hive thermostats. All you need to do is head to their online shop and use the code HIVE20 before checking out.

Time to turn up the heat (and then turn it down again, when the weather's better, or you go out)…

Our pick of the best smart thermostats

1. Nest Learning Thermostat

Smart, easy-to-use, and suprisingly sexy

Display: 5.3cm, 480x480, 229ppi LCD
Sensors: Temperature, Humidity, Near-field activity, Far-field activity, Ambient light
Connectivity: 802.11b/g/n Wi-Fi (2.4GHz/5GHz); 802.15.4 (2.4GHz); Bluetooth Low Energy (BLE)
Compatibility: Combi boilers; System and heat-only boilers; Domestic hot water tanks; Hydronic underfloor systems; Air-source and ground-source heat pumps (heating only); Zoned systems (one Nest Thermostat per zone); Heating systems with OpenTherm technology
Colours: Stainless Steel; Copper; Black; White
Reasons to buy
+Third-generation model+Easy to use+Learns as you go+Can be controlled from your tablet or smartphone+Cost includes expert installation
Reasons to avoid
-There are cheaper alternatives

Nest takes Apple-like care in the design of its products – hardly surprising as it was set up by ex-Apple people. This is most evident in the way it turned the common and extraordinarily ugly smoke alarm into something that's actually rather attractive.

The same ethos was originally applied to its Nest Learning Thermostat, which kickstarted the smart thermostat gold rush, and clearly informs Hive's move from its functional but dull original incarnation to the Yves Béhar-designed, red-hot sex box you see below.

The Nest Learning Thermostat monitors the user's habits and will control the heating accordingly. So for instance, if you regularly go to bed at, say, 11pm, the system will learn your behaviour patterns and turn the system off when necessary. It's easy to program an on/off schedule using the excellent Nest app but this might not even be required since the unit also has activity sensors on board so it can detect if no-one's home and adjust/turn off the heat accordingly.

The circular glass interface, meanwhile, is a beautiful thing to behold and so incredibly simple use; all you require is an opposable thumb and a forefinger. The Nest Learning Thermostat comes with everything required to fit it DIY style but you'd be far better off having an engineer do it, especially as the £279 price includes installation. With Google Home and Amazon Echo integration adding voice control, it's our hot pick.

2. British Gas Hive

Display: not stated
Sensors: not stated
Connectivity: not stated
Compatibility: not stated
Colours: not stated
Reasons to buy
+App and thermostat are easy to use+Modern, minimalist design+Extensible with Hive smart home products+You don't have to be a British Gas customer to buy it
Reasons to avoid
-Not as good-looking as the Nest

Given that Hive is a British Gas innovation, chances are this is the thermostat you'll most likely be using. And very good it is, too. The Hive system is fitted by a qualified engineer and incorporates three pieces of kit: a boiler receiver, an internet router hub and a wall-mounted thermostat.

The thermostat itself may not be quite so handsome as the Nest, but it's a good looking thing nonetheless, and ridiculously easy to use. That's also true of the accompanying iOS and Android app, which lets you change the temperature or the on/off schedule from anywhere there's a cellular or Wi-Fi connection. 

It also means you can automatically set the heating to turn off when you (and anyone else in the household with the Hive app) leave the house and then come back on as you approach again. Notifications mean that this won't plunge the rest of the family into the cold just because you've popped to the shops.

The app is is a joy to use and also encompasses the wherewithal to control future Hive smart home products, including light bulbs and plug sockets. Safe choice.

Hive has also now released a range of compatible products, including a motion sensor, window/door sensor, and smart plugs. Which is pretty helpful if you want to dip your toes into smart home waters.

You can buy Hive as part of a smart home subscription package, with ongoing care and user tips. Given that Hive's system is so user-friendly, we'd recommend buying outright, unless you're a total dunderhead. Oh, and it's Alexa and Google Assistant compatible too, and works very nicely with her and it.

3. Tado Smart Thermostat

Minimalist, effcient and easy to use

Display: 32x20mm LED matrix display, comprising 10x19 LEDs
Sensors: Temperature; Humidity; Ambient Light
Connectivity: 868MHz, Mesh (6LoWPAN)
Compatibility: Worcester, Baxi, Vaillant, Potterton, Ideal... ; Supports both 230V and extra low voltage interfaces (digital bus/analogue); Combi, system and heat-only boilers; Conventional and condensing boilers; Common Y-, S- and W-plan setups; Relay compatible, both switched live systems and potential free (dry contact) systems; Compatible with the UK standard backplate; Hydronic underfloor systems; Electric underfloor systems with a maximum switching current of 6A; Air source and ground source heat pumps (heating only); Zoned systems (one Smart Thermostat per zone)
Colours: White
Reasons to buy
+Easy to use thermostat and app+Geofencing capability+Works with 95% of central heating systems+Valves have a display too
Reasons to avoid
-Less aesthetically pleasing than Hive and Nest

The Tado (or tadoº, to give its 'proper' name) Smart Thermostat connects to a wider range of heating systems than Nest. In fact, it works with 95% of current heating systems, whether a combi or conventional boiler, or an electric under-floor setup, and can also control your hot water. Although, as with most smart thermostats, installation is best carried out by a qualified engineer.

So what's so good about this model? It's smart enough to learn about the layout of a user's home and soon has the specific heat capacity of your house worked out, so if you want it to be 18 degrees at 7am, it'll fire up in advance if needed.

Arguably the real killer feature is Tado's use of geofencing, though. By tracking the proximity of your mobile, when it detects you're on the way home, it can turn up the heat so it's toasty on your return.

The app is programmable, like a normal thermostat, and can be manually overridden when required. It also displays all kinds of information about your energy use, although the key money-saving stats are dependent on your input, a bit like calorie tracking with a fitness band.

As well as the £199 unit price, there are other extras to consider, including an Extension Kit – you'll need this if your current system has no wired room thermostat, which is true of most modern systems or a set of smart radiator valves.

Tado now does a range of smart radiator valves that can be used with or without the thermostat. These are preferable to rivals from Eve and Wiser, as they are more attractive, less bulbous, and have a neat little screen to display the current temperature, without you having to dig into your mobile app.

Tado also works with Alexa and Siri, which is great.

Drayton Wiser

4. Drayton Wiser Multizone Kit 1

Easy, affordable and versatile thermostat/valve systems

Display: not stated
Sensors: none
Connectivity: Wi-Fi
Compatibility: Combi boilers; System and heat-only boilers (depending on Wiser system chosen)
Colours: white
Reasons to buy
+Easy to install on reasonably modern systems+Versatile and precise heat control+Alexa voice control
Reasons to avoid
-Lacks smart bells and whistles-Not exactly the sexiest things ever

Removing much of the designer sex appeal and clever-cleverness of the Hive and Nest systems, but adding utility, Drayton's affordable range of Wiser systems could be just the thing for many users.

They do various setups for single and multi-zone heating and hot water systems but the one that seems best to us is just a thermostat that slots into place where your existing one was and two radiator valves that also go in place of existing ones. That means you can set a temperature for the whole house, or have a warmer front room and cooler bedroom, or shut off heat in underused rooms entirely.

As long as your system is fairly modern, this takes minutes and involves no spanners or getting wet. If it's old and decrepit, you'll have to get a plumber in, but you'll reap the benefits longer term. 

You can add further smart valves if you want a different temperature/heating programme in every room, or use the main thermostat the old-fashioned way, via the Wiser app or Alexa. 

Some users  do complain of reception problems between Wiser and their routers, but it was fine for us. It's worth noting also that Drayton is a proper plumbing company rather than a tech one, which feels like a reassuring factoid. 

Wiser has also just added geofencing options via the app, so heat can be turned off when you leave, and compatibility with IFTTT. We haven't tested these yet, but they do make it much more on a level with the likes of Nest, Hive and Tado.

(Image: © Netatmo)

5. Netatmo by Starck

Affordable smart thermostat with a few limitations

Display: E-Paper display
Sensors: Temperature
Connectivity: 802.11b/g/n Wi-Fi (2.4GHz)
Compatibility: Gas, oil, wood boilers and heat pumps (replaces existing wired and wireless thermostats)
Colours: Interchangeable, using 4 colour adhesives (supplied)
Reasons to buy
+Easy to use thermostat and app+Energy saving+Relatively affordable+Wireless operation
Reasons to avoid
-Old-fashioned E-Ink display-Design is nothing special-Less features than the Nest

Netatmo, the French company that revolutionised the home weather station, has employed the services of product designer and Frenchman Philippe Starck to create its take on the humble thermostat.

And here it is, a translucent plexiglass cube with a simple display. Given that it's designed by one of Europe's foremost creatives, The Netatmo's old-fashioned black E-Ink display and white casing is a little bit, er, ordinary, especially when placed alongside something like the Nest. But hey, looks aren't everything. Netatmo predicts its thermostat will save the average user about 37% in energy costs, so that's a bonus.

Again, everything here is controlled via the free Android and iOS app and set up is a doddle. On initial installation, it'll ask you five simple questions and then create a schedule based on your lifestyle. Another very cool feature is that the thermostat itself can be installed in two ways: as a wired replacement for your current unit or wirelessly, using three AAA batteries. The wireless option allows you to place the thermostat in any room which is handy if you use one room more than the another.

The Netatmo is also one of the cheaper options here, though it's not as well equipped as the marginally more expensive Nest, and IMO, not as pretty.

The Netatmo works with EDF Energy's HeatSmart, which is available for £199 including installation.

6. Climote

Versatile thermostat with easy controls

Display: not stated
Sensors: not stated
Connectivity: not stated
Compatibility: not stated
Colours: not stated
Reasons to buy
+Easy to use thermostat and app+Can be controlled by text message (SMS)+Embedded SIM – no broadband connection required
Reasons to avoid
-Monthly subscription for remote access service

Don't underestimate this system. Unlike most app-controlled thermostat set ups, Climote can control three zones at once, straight out of the box. And it doesn't rely on a broadband connection either because, rather like the Kindle, a SIM card is embedded into the device which allows for communication over GPRS.

Furthermore, you can control the system remotely in three different ways, either using the instinctive iOS/Andoid app, via a browser or, get this, from a bog-standard unsmart phone; you know, like that old QWERTY Nokia you still have in your kitchen drawer.

Mind, this remote access service does cost €3.69 per month (payable annually in advance) which could be a spoiler for some. Installation by a Climote-endorsed engineer takes a purported 30 minutes and that's pretty nifty.

(Image: © Honeywell)

7. Honeywell Lyric T6/T6R

Easy-to-use smart thermostat – with limitations

Display: not stated
Sensors: Temperature
Connectivity: Wi-Fi
Compatibility: Heating systems with OpenTherm technology; Common Y- and S-plan setups
Colours: not stated
Reasons to buy
+Easy to use+Geofencing works well+Apple HomeKit and Amazon Alexa compatible
Reasons to avoid
-Needs professional installation-Limited programming options

Looking like a cross between the British Gas Hive and the Nest, the Lyric T6 is the latest in a long line of smart connected devices from the highly-regarded Honeywell with wired and wireless table-top (T6R) versions available.

The Honeywell Lyric T6(R) can be controlled either via its touchscreen or via the free Honeywell Lyric smartphone app, with built-in geofencing so the system automatically knows to switch on and off depending on how close you, or other members of your household, are to home. It also works with Amazon's Alexa and is Apple HomeKit ready.

As with other smart thermostats, the Honeywell Lyric T6 is best fitted by a professional installer, since the supplied box that connects to your boiler (or second zone) needs to be connected to the mains. Once installed and setup, however, the system is easy to use – although there are some limitations.

You use either geolocation or a range of programmable modes to configure what time / temperature the heating switches on and off at but, unfortunately, you can't use both these options together – a shortcoming the Tado, for example, simply doesn't have.

One thing we definitely like though is the Lyric T6's Optimised Start mode, which automatically fires up the heating early so your home is already add the right temperature when you wake up – just the job for those cold winter mornings.

8. Heat Genius

The all-singing wireless system

Display: not stated
Sensors: not stated
Connectivity: not stated
Compatibility: not stated
Colours: not stated
Reasons to buy
+Easy to use thermostat and app+Control your system from anywhere
Reasons to avoid
-Relatively expensive-Complex installation – not for DIYers-TRVs not included in Starter Kit-Uninspired design

Sexy it is not, but if you want full heating control of individual rooms and budget isn't a concern, you might consider this all-singing wireless system.

The app-controlled Genius is more complex than the Nest, Hive or Tado so fitting it yourself isn't really an advisable option. The system comprises a Heat Genius controller that plugs into your Wi-Fi router, a boiler controller and a portable wireless thermostat that can be moved from room to room.

For full individual room control, Heat Genius also installs a TRV (thermostatic radiator valve) on each rad so you can create different schedules for different rooms. And if you fit the optional wireless motion sensor-cum-thermometer, the system will also detect whether you're in or out, and create its own set of schedules accordingly.

The Heat Genius system isn't cheap – the Genius Starter + Hot Water On/Off kit without radiator valves and room sensors costs £295 – but the claimed savings of as much as 50% a year in heating bills do make it tempting for well-off owners of larger homes.

9. Heatmiser Neo

HomeKit-compatible, but needs pro installation

Display: Blue backlit screen
Sensors: Temperature; Air
Connectivity: Wireless Mesh Network (via neoHub)
Compatibility: not stated **Colours** Sapphire Black; Glacier White; Platinum Silver
Reasons to buy
+Easy to use smart thermostat and app+HomeKit compatible+Includes geofencing
Reasons to avoid
-Professional installation needed-Options list can be confusing

This zonal system is similar to Heat Genius, only it's fully wired, which means a) installation should be carried out by a pro and b) your walls will likely need to have conduits installed. 

It's a much more baffling system to get one's head around, mind, since there's a bewildering assortment of different mix-and-match options available. In this respect you're advised to contact Heatmiser direct to discuss your needs.

Having said that, a wireless version of the Heatmiser system (not tested here) is  also available in kit form. Dubbed, the neoAir Kit Gen 2, it comprises a neoAir smart thermostat, a second-generation neoHub and an RF switch and is capable of being DIY installed.

Both wired Neo and wireless NeoAir versions are Apple HomeKit compatible.