Best smart thermostat

Honeywell makes a range of smart thermostats, including the Honeywell T6 series, priced from around £150. The T6 model is wall-mounted, the T6R wireless can sit on a tabletop, and the T6R-HW can control your hot water and heating, but it is also more expensive. People who've bought the Honeywell T6 like the app's ease of use, that it works with Voiceover, and that you can programme the thermostat directly if your wi-fi or internet connection goes down. Features of the T6 model include:

• Being compatible with Apple HomeKit (requires iOS 8.1 or later), Google Home, Amazon Alexa and IFTTT (If This Then That, which allows you to integrate different apps, services, and devices). The app works with Apple's VoiceOver and Siri, as well as Android's TalkBack.
• Using the location feature on your smartphone to adapt your home heating. For example, it saves energy when you're out and adjusts the temperature when on your way home. People who've used the thermostat note you have to choose between a schedule or using the geofencing feature.
• The option of different heating schedules, from 24-hour blocks to weekend and weekday schedules, which you can programme using the Honeywell app or the thermostat itself.
• A touchscreen interface that is always backlit, with the ability to choose the light level that suits you.

The T6 model isn't weather-responsive or able to learn from your routines to automatically create a heating schedule for you.

An alternative to the T6 is the Honeywell Evohome wifi-connected thermostat pack. This is more expensive (around £250) and requires professional installation. However, it has intuitive programming which can intelligently optimise your heating schedule, and you can use it to create and control up to 12 heating zones around your home.

• Nest Learning thermostat defaults to an automatic schedule based on learning your routine and preferences as you turn the temperature up and down when you first use it.
• It's compatible with Amazon Alexa, Google Home, and IFTTT, but not Apple HomeKit.
• The thermostat controls your hot water and central heating, with a boost function allowing you to top up your hot water when needed.
• Use your phone's location and the sensor on the thermostat it detects when you're away from home to save energy. The motion sensor also detects when you're nearby and turns on the display backlight.
• You can create multi-zonal heating by adding up to 20 thermostats.

This thermostat isn't weather-responsive, and for those who prefer to programme their heating schedule, this can be a little complicated. Google recommend booking professional installation for this thermostat.

The Nest Thermostat E retails with Google for £199, but prices at other retailers vary, and you may get it cheaper by shopping around. Many people who've chosen this thermostat like the fact that it's possible to install this yourself, saving money on the cost of professional installation

• As with the Nest Learning thermostat, this model is compatible with Amazon Alexa, Google Home Assistant, and IFTTT, but not Apple HomeKit. The app is generally accessible with leading screen readers.
• The Nest Thermostat E features an automatic schedule created based on learning your preferences over a few days and a basic heating schedule you can use as soon as it's installed. It also comes with a stand which lets you place it on a table or desk in any room you like.
• The thermostat knows when you're at home or away and turns the heating down when you're out.

The main differences between this and the Nest Learning thermostat are that this model doesn't control your hot water or allow you to set up multi-room heating with multiple thermostats. 

The Tado smart thermostat starter kit retails for about £180. Many people who've bought this thermostat said they found it easy to install and like the device's simple, clean design.

• The Tado smart thermostat works with Amazon Alexa, Google Home and Apple HomeKit.
• You can create multi-zone heating control by adding smart radiator valves.
• This thermostat is weather responsive, meaning it will adjust the temperature based on the weather outside.
• Features such as open window detection and geolocation are available. However, some functions, such as switching off automatically when you're out, will only work if you subscribe to the Auto-Assist skill in the app at extra cost.
• The thermostat doesn't control your hot water, but you can buy an extension kit that enables this.

Hive recently introduced the Hive Thermostat Mini, costing from £119 plus installation. This is a more accessible price point than the original Hive Thermostat and has many of the same features and benefits. Hive products rely on a hub that plugs into your broadband router with an ethernet cable. Hive also makes smart thermostatic radiator valves, smart plugs and security cameras. People who've bought Hive thermostats like that text on the app can be adjusted to make the size bigger, and the range of features at a lower price. Some people note that you must touch the thermostat to see the display and that it times out quite quickly. They also found that the app freezes while the software is being updated.

• The Hive Thermostat Mini can control your heating and hot water using the Hive app and has a boost function which means you can top up your usual schedule with extra hours of heating and hot water.
• It's compatible with Alexa, Google Assistant, Apple HomeKit, Siri shortcuts and IFTTT.
• It uses geolocation to let you know if the heating is on when you're away from home (but you'll have to use the app to switch the heating off, it doesn't do this for you).
• Additional features include frost protection which automatically switches the heating on if there's a risk of pipes freezing.
• Multi-zonal control allows you to control up to six different areas in your home.

There are limited controls on the thermostat, so you need to use the app to make the most of its features, such as boosting the heating or hot water and creating and reviewing your schedule.
To get information about your energy use and energy-saving tips from Hive, you have to pay for a Hive plus subscription, an ongoing cost, in addition to the price of the thermostat. Unless you're competent in electrical wiring and DIY, you'll need to get the Hive thermostat professionally installed.

The Netatmo thermostat retails from around £150. People who've bought this thermostat like the quality of information the app provides about energy usage and efficiency. Many also said they found it easy to install.

• Works with Amazon Alexa, Google Home and Apple HomeKit. The app is accessible with Apple's VoiceOver and Android's TalkBack screen readers, though some features could be easier to use.
• Adding up to 20 smart radiator valves (purchased separately) allows you to control the temperature in different spaces throughout your home.
• The thermostat has a child lock, eco mode, and frost protection when you're away from home.

The Netatmo thermostat doesn't give you hot water control and isn't weather-responsive. It doesn't have geolocation, so it can't adjust your heating depending on where you are.