Smart heating and thermostats are big business right now, and in many cases consumers are hungrier for connected tech in their home than they are on their wrists.
So what exactly does a smart thermostat do? Well, they're designed to give you control over your home heating from your smartphone or wearable like a smartwatch. Some are intelligent, so they will learn your habits for when you'll really need that burst of warmth.
Heating your home intelligently can mean cash savings of around a year – so it's little wonder they're selling so fast.
Essential reading: Best smart home tech
There's never been a bigger or better selection of smart thermostat packages, but as always, there's still a dizzying array of options to chose from. Working out the differences between these systems isn't straightforward, so we've picked out the key points for you below.
Nest boss Tony Fadell helped make the original iPod when he worked at Apple, and as you might imagine, design aesthetic is an important part of his Nest thermostat.
You can buy Nest off the shelf but you'll need a professional 20-minute installation to hook it into your boiler, and place the sensor somewhere prominent in your home.
Smart home showdown: Nest versus Hive
After that, you can set programs for your home, and Nest will learn your habits – tinkering with your aircon/heating system, turning it off when it knows you're not at home, and restarting it when you're coming back. It will also heat or cool your home when the energy prices are cheaper, which will save you bags of cash.
The new 3rd generation Nest thermostat can now control your hot water tank, includes new OpenTherm technology to help your heating system work more efficiently and that's all wrapped up in a slimmer, sleeker design.
Hive, which made it into our Wareable 50 watchlist, is owned by British Gas, but you don't have to buy your energy from them. The battery powered Hive enables you to control your home's heating from anywhere: smartphone, tablet or Web browser, and create complex schedules for your heating.
The latest model is designed by Yves Behar (Jambox and August Smart Lock) with a collection of customised frames available to make it a better fit inside your home.
Hive works with 99% of boilers, giving you the option of separate controls for hot water tanks (most homes now have a combi-boiler). It's packed with features giving you the ability to control hot water, set reminders when you're out of the country and includes a frost protection mode to turn the heating on when the temperature really drops.
The apps for iOS and Android are well-done and can use location triggers, and if you're an existing Hive customer, you can upgrade to the new thermostat for £99.
Tado is a remote autopilot for your heating system, using an app (iOS, Android and Windows 10 Mobile) to work out where you are and adjust the internal temperature of your home accordingly.
Unlike Nest, it runs on batteries, so you can place it pretty much anywhere. You may need to pay an additional £80 for an extension box depending on your current setup but it's one of the easiest systems to install yourself.
Tado recently introduced the ability to control multiple heating zones from additional thermostats (£179 or £6.99 a month) and is set to launch a smart radiator valve in 2016. If you own an Android Wear smartwatch, you can now control features from your wrist while the new IFTTT support means you can set up recipes leaving the Tado to get on with what it does best.
The Irish smart thermostat company is currently offering its setup to Scottish Power customers with a 30-minute installation, letting you take control of your heating and when the hot water comes on.
It's based around a three zone system focusing on warming up specific rooms in your home. You can control via your desktop, iOS or Android companion apps and even send SMS text commands to set schedules and deliver heating boost when it's really cold.
The hardware features an iPod-esque click wheel to scroll through modes and you can add additional thermostats if you decide you want to spread the heating love to the rest of the house.
The Starck-designed thermostat is one of the most affordable entries in our list and you can now get one professionally installed courtesy of EDF Energy in the UK.
Aside from its good looks, the Netatmo will let you remotely control heating from the iOS, Android or Windows 10 Mobile companion apps. An auto adapt feature can predict heating periods and you'll also get customised Energy Savings report to see how you can shave off more than a few pennies off the heating bill.
It also has Nest-style learning algorithms that monitor your behaviour and can set your heating automatically based on the way you've set it in the past. It can even take weather conditions into account so your heating system doesn't freeze over during the winter.
Honeywell's evohome offers individual wireless radiator valves for every room, letting you set up to 12 heating zones, which can then be controlled from the main tablet interface. So, you can stay nice and toasty watching telly in the evening without wasting money keeping the rest of your pad at tropical temperatures.
The Honeywell Voice Controlled Thermostat also has the ability to adapt to your accent so that it can better respond to your wishes. Like Tado, Honeywell has also added IFTTT support letting you create recipes based on location and your calendar to turn it on or off whether you're home or away.
How much you pay for Heat Genius depends on how many rooms you have in your house—it can easily reach £600-700—but it does more than the other systems we've covered here, and you really need to think of it as an investment that will reduce your energy bills over time.
The big extra here is room-by-room heating, and it can automatically detect which zones are occupied and which aren't. Essentially it's the ultimate in smart home heating—the full-fat option, if you're ready to pay for it.
A lot of the system is managed automatically via sensors and switches, but the apps for iOS and Android give you extra control and feedback.
From £249.99, heatgenius.co.uk
Like Heat Genius, HeatMiser gives you multi-room control over your heating, and costs extra because of all the extra kit you're going to need. A variety of configurations are available depending on what you need.
The hardware is attractive, the apps are well-crafted, and it's one of the most comprehensive options out there—give it a look if you want as much control as possible (it includes air and floor sensors, for example).
Apps are available for iOS and Android and it does include features like location tracking. New features include a wireless option, the ability to set up recipes and Apple Watch compatibility so you can control heating effortlessly from your wrist.