The 6 best smart thermostats to cut energy bills and control heating remotely

Smart thermostats let you manage your heating system remotely – either through an app on your phone or tablet, or via a voice assistant like Alexa. This means that even if you're at work or on holiday, you can keep an eye on your home's temperature, adjust it, and even set an automated timer so it's toasty when you arrive.

Some models can even learn your daily routine and automatically adjust based on whether you're home, asleep or away, helping to minimise unnecessary heating and, as a result, reduce your energy bills.

To help you find the best smart thermostat, we've rounded up six of our favourite options below, with all the details you need to know about heating system compatibility, smart home integration, and special features. To find out why Tado's Smart Thermostat X scored top points, keep reading.

The quick list

Short on time? Here’s a quick overview of the best smart thermostats – including quick links to more information.

The best smart thermostat overall

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What stood out the most about the Tado Smart Thermostat X is its compatibility with a range of different heating systems – whether you have a combi or system boiler, underfloor heating, or heat pumps – making it a great choice for most homes.

The LCD device is sleek and discreet, displaying the exact temperature of the room in Celsius, along with manual control buttons. You can also adjust the temperature remotely via the smartphone app or through smart home platforms such as Matter, Amazon Alexa, Apple HomeKit, Google Home, the iOS app, or the Android app.

The device helps your home maintain a constant temperature, with the ability to create customised schedules for each room in the house. There is also the option to buy a Tado AI Assist subscription for £3.99 per month, which enables you to pre-heat your home before you arrive, view real-time reports on your energy consumption and costs, benefit from open-window detection, and access air quality optimisation. The thermostat can even detect when you're out to avoid wasting energy.

If you want special features, such as geo-fencing, without paying an additional premium, the Honeywell Home T6R-HW Smart Thermostat is a good alternative (unless you have a heat pump).

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The best smart thermostat runner-up

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The Honeywell Home T6R-HW Smart Thermostat can be used with any boiler or underfloor heating system and helps improve the energy efficiency of your home.

The temperature can be adjusted manually on the interface or through an app or voice assistant (including Amazon Alexa, Apple HomeKit, Google Home, the iOS app, or the Android app). There is also the option to program a seven-day schedule with six set points – perfect if you have a regular routine.

This smart thermostat can be used to control both your heating and hot water, and it features a "boost" function for a temporary override, so you always have access to a warm shower. There are lots of settings to choose from, including Auto (a programmed schedule), Manual (maintains a constant temperature), Eco (maintains an energy-efficient temperature), and Holiday (a reduced set temperature for when you are away).

We think this is a solid option, but if your home is powered by a heat pump, the Cielo Smart Thermostat Eco may be a better choice.

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The best smart thermostat for combi boilers

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The Hive Mini V4 Smart Thermostat has the stamp of approval from Homebuilding's Editor, Beth Murton, and Assistant Editor, Sarah Harley, both of whom have one installed in their homes. It’s suitable for combi boilers and can be controlled manually via the touchscreen display, an app, or a voice assistant (Amazon Alexa, Apple HomeKit, and Google Home).

This battery-powered device is OpenTherm compatible and offers frost protection for your pipes, a heating boost of up to six hours, and the ability to schedule up to six time slots each day.

Sarah has the hubless version (available on Screwfix) and loves how easily she can control her heating with the click of a button on her phone – whether that’s adjusting her schedule, boosting the heating, or turning it down when it gets too warm.

"That said, I think you have to be careful about where you place portable thermostats like this, as it's assessing the temperature based on only one room or space. It's not necessarily a Hive issue, but something to consider when thinking about where to locate your smart thermostat," she adds.

"However, the fact this one is portable does make it easier to trial it in different rooms, so you can establish which room will give you the most even temperature across your property."

Don't have a combi boiler? There is also a version for system and heat only boilers from Screwfix.

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The best smart thermostat for zone control

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If you want precise temperature control across multiple rooms, we recommend the Honeywell Home Evohome Smart Thermostat, which lets you manage up to 12 different heating zones.

The thermostat has a large touchscreen that displays the temperature of each room and the hot water, as well as a control panel. These features can also be accessed remotely via a smartphone app or through your Amazon Alexa, Google Home, and IFTTT devices.

You’ll be able to set up an individual seven-day schedule for each room (including six time slots per day), which can be optimised based on the outside temperature, room temperature, and set point. Since it automatically learns your home’s heat capacity, your boiler will run at the lowest possible rate.

The wireless design makes it portable and easy to install, and it’s compatible with 24–230V on/off and OpenTherm appliances, including boilers, zone valves, heat pumps, and district heating systems.

If you're looking for something more affordable, we recommend the Cielo Smart Thermostat Eco, which is around £90 cheaper.

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The best smart thermostat for radiators

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These smart thermostatic radiator heads will keep your room at the optimal temperature, controlled via the touchscreen interface, mobile app, or smart platform voice-assistant.

They are compatible with most radiators and each pack comes with six different adaptors for various valve types, including Danfoss (RA, RAV, RAVL), Comap, Herz, Terrier, Siemens, and Olymp. This smart thermostat can be self-installed within five minutes and is powered by a convienient rechargeable battery.

Overtime, the device will learn the heating pattern of each room to strike the perfect balance between energy-efficiency and comfort (while still giving you total control). It can also detect when you're out and about, so you never waste money on heating an empty home, and it will put it back on for your arrival.

Similarly to the Tado Smart Thermostat X, some features, such as geofencing, air quality optimisation and open-window detection, require a £3.99 monthly subscription, but you can still access remote control without this. If that's a problem, you could consider the Honeywell Home T6R-HW Smart Thermostat instead.

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The best smart thermostat for heat pumps

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This smart thermostat by Cielo can be used with heat pumps, boilers, and geothermal heating systems, and can be controlled via the device itself, a smartphone app, or smart home integration.

The device allows you to monitor your heating from anywhere in the world, adjusting the temperature, setting schedules, and using preset options for Home, Away, and Sleep to reduce your energy bills. It also features geofencing for location-based control, which turns off the heating when you're not there.

The thermostat keeps track of your home's heating and cooling patterns (which you can view yourself) and uses this information to lower your energy consumption. It's easy to install and comes with a backplate, wall plate, USB-C adaptor, and mounting screws with drywall anchors.

For more advanced controls, such as detailed scheduling and room zoning, the Honeywell Home Evohome Smart Thermostat is a better choice.

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Other smart thermostats we tested

Who tested the best smart thermostats

Curious about who’s behind these reviews? Meet the team below:

Curated by

Curated by

Megan Milstead

This buying guide was curated by Homebuilding’s content editor, Megan Milstead. She tested the Nest Learning Thermostat.

Beth Murton

Homebuilding's editor, Beth Murton, tested the Hive Mini V4 Wireless Heating OpenTherm Smart Thermostat.

Sarah Harley

Sarah Harley, Homebuilding's assistant editor, also tested the Hive Mini V4 Wireless Heating OpenTherm Smart Thermostat.

For more information on our testing procedure, read our dedicated page on how we test products.

How to choose the best smart thermostat

Before investing in the best smart thermostat, you'll need to consider the following:

1. Your heating system
Not every smart thermostat will be compatible with your heating system, so you'll need to check its suitability first. If you'd like to buy one of the models in this guide, we’ve included this information in the table below.

2. Your schedule
In some cases – such as the open window detection feature on Tado devices – certain special features come at an additional cost. To avoid wasting money each month, think carefully about which features you will actually use and need on a daily basis.

3. Installation
While some smart thermostats are as simple as plugging them in and getting started, others require professional installation.

"Many smart thermostats are designed for DIY installation, offering clear instructions and guidance on how to safely install them," says Chris Houghton, operational improvement manager and qualified gas and heating engineer at Ding.

"However, it is important to note that wiring will still be necessary, so if you would rather not have to deal with something like that, you can book engineers to set one up for you.”

What are the pros and cons of a smart thermostat?

If you're feeling undecided on whether a smart thermostat is right for you, Michael Zohouri, Founder of Pyramid Eco, outlines the pros and cons below:

✅Control: "The biggest advantage of a smart thermostat is control. You can adjust the set temperature from your phone and set schedules to match your daily routine."

✅Reduce energy bills: "You can also see how much energy you’re using. That alone can help you save on your bills as you see when you’re wasting energy heating an empty house. And if you forget to turn the heating down before you leave the house, you can use you phone to turn it down. Some systems learn your habits over time and adjust automatically."

✅Zoning: "Some more advanced systems allow you to control different rooms separately when paired with smart radiator valves. That means you’re not heating the whole house just to use one room."

❌More expensive: "They are more expensive than a standard programmable thermostat. Installation can be straightforward, but in some older properties with older wiring, you may need a professional to set it up properly."

❌Savings depend on how you use it: "If someone simply installs a smart thermostat and leaves it running at 21 degrees all day, they won’t see much difference. It’s a tool, not a magic fix."

Michael Zohouri

Michael Zohouri is the founder of Pyramid Eco. He is a heating and retrofit specialist with over a decade of experience installing smart heating controls, heat pumps and energy-efficient systems across UK homes.

When used correctly and optimised for your space and lifestyle, the best smart thermostats can be invaluable in reducing energy bills and making your home more efficient.

To learn more, read our guide on smart heating systems and the cost of replacing a thermostat.

Edited by Beth Murton.