Climate action: 11 steps to smart heating

When we talk about smart heating, we mean using systems that allow you to heat your home only when and where it’s needed. By controlling your heating systems via your home wifi, it can delay your heating if you’re going to be late home or choose to only heat the room you're spending time in.

Studies have shown that if used and understood, a smart thermostat can cut your energy use by 10%, compared to a traditional one. At the same time, using your heating controls to reduce temperatures to between 18C and 21C, if appropriate health wise, can also save you money and carbon emissions.

Below we provide a step-by-step guide to setting up smart thermostats and smart radiator valves. We also outline everything you need to know about smart metres and smart tariffs. 

How to do smart heating

While it may sound techy and confusing, smart heating is easier to install and use than you expect.

Smart heating involves using a smart thermostat. Smart thermostats allow you to (either manually or automatically) match your heating to your schedule and behaviour, so that you waste less energy. Smart heating also sometimes involves getting smart radiator valves so that you can control each room separately.

Smart thermostats

Smart thermostats are key to smart heating. Not to be confused with smart meters, they can offer sophisticated systems for controlling your heating across your home.

Smart thermostats are a bit of an investment, costing around £100 - £330, once you factor in the unit and installation. Given the high cost of energy at the moment, though, they may very quickly be a worthwhile investment. If you made the full 10% energy saving, the average household would have made back the cost of their smart thermostat in one to two years.

If choosing a smart thermostat, here are a few things to consider, to ensure you get the right one:

1. Decide how you want to control it

Lots of smart thermostats are controlled through mobile or tablet apps. If you don’t have a smartphone or tablet, you’ll need to look for a model that you’re able to control through your computer.

Smart thermostats can also be compatible with other smart devices (such as Google assistant). This means that if you have a smart device, you can control your thermostat using voice instructions, for example: “Turn hot water on at 5pm.”

2. Decide whether you want it to be automated or in your control

Some smart thermostat devices connect to an app on your phone that allow you to control your own heating. Others ‘learn’ your patterns and preferences before making a personalised schedule.

Some have sensors or track your smartphone’s geolocation, and can switch off the heating when you’ve left and switch it back on when you return to your home!

Work out what level of control you want vs what you’d like to be automated. For example, is it realistic that you’ll remember to change your heating if you’re later than usual coming home, or are you better getting an automated option? Do you mind an app tracking your location?

Many thermostat apps offer options somewhere between entirely manual and entirely automated. For example, some will alert you if your heating comes on when it thinks you’re away from home, while others will automatically turn it off for you.

Be realistic about your tech expertise. If you hate using your smartphone, choose a simpler option. In this case, it might be worth reading a couple of reviews or doing an internet search on the simplest thermostats to control.

3. Decide whether you want it to control your hot water

Some smart thermostats allow you to control your hot water. This might be very useful if you spend a lot of time away from home, for example, as it allows you to switch the hot water off while away but turn it back on in time for a hot shower when you get home. Some smart thermostats may charge more for this function.

If you have a combination boiler, you won’t need a smart thermostat that controls your hot water.

4. Look for a model that uses OpenTherm

OpenTherm is a special system that you can use as an add-on for your smart thermostat, which further controls the way that your boiler heats up water. It is essentially a ‘digital language’ that allows your boiler and smart thermostat to communicate. Rather than firing up your boiler and then allowing it to cool, it uses information from your smart thermostat to get a more consistent temperature. This is much more efficient, saving energy.

Back in 2018, the Trusted Reviews website claimed that using OpenTherm could give 6% energy savings, on top of anything else your smart thermostat will already do. So you may well want to consider ensuring that OpenTherm is part of your smart heating set up.

Not all boilers and smart thermostats will be compatible with OpenTherm, so you will need to check this. Usually compatible boilers will have the OpenTherm logo on them. You can also check in your manual or call the manufacturer.

5. Think about how big your house is

If you have a large house with multiple rooms, you might want to install a system with several smart thermostats that offer ‘multi-zone heating’. This means that you’ll be able to heat some areas of your house without heating others. 

You can also link thermostats with smart thermostatic radiator valves, so you can heat each room separately. We discuss how to choose smart thermostatic radiator valves in the box-out below.

Different thermostats will allow a different number of 'zones', from 3 to over thirty. Think about how many different zones you’d want. You may also have to buy a separate control for each room, putting up the cost of your smart heating, so consider this before deciding.

6. Identify any other features you might want

Smart thermostats can have other useful features. For example:

• Using data from weather services to adapt your heating to match the conditions outside (although how useful this actually is is unclear).
• Detecting draughts for you.
• Safety or holiday modes to protect your pipes from freezing when you’re away.
• Voice control, so you can change settings from your sofa.
• Linking up with your other smart devices, e.g. smart speakers.
• Interfacing with your heat-pump.

You may want to write out a list of your behaviours, then decide the features you need. For example, are you away a lot? Is your schedule unpredictable?

7. Think about price

You’re likely to make back the price of a smart thermostat within a couple years from savings on your energy bill. Nonetheless, they do come with quite a bit of an upfront cost, at a few hundred pounds. It could be worth setting a target date for installation, and then putting a bit aside until you have enough saved up.

When working out how much your thermostat is likely to cost, remember to factor in installation (if not included with the unit) and the price of a connecting device (see below).

You may also want to spend some money on smart radiator valves or extra thermostats for multi-zone heating: each addition will come at a price. Luckily, you can add extra valves or thermostats later down the line as and when you can afford them. If you plan to do this, it’s worth knowing what your ideal set up would be so that you can ensure that whatever you buy to begin with will enable that to happen.

Smart heating can seem expensive if you’re not sure how long you’ll stay in your home or if you're renting. Luckily, you can often take your smart thermostat with you when you move and just attach it to your new boiler – see below for more on this.

8. Check which models are compatible with your heating system

Once you have narrowed your smart thermostat down to a few possible models, you will need to check that they are compatible with your boiler or heat-pump.

Most modern boilers will be compatible with smart thermostats, particularly if already connected to a regular thermostat. However, it’s worth checking with your boiler manufacturer once you’ve chosen a particular smart thermostat model, before buying.

If you’re thinking of getting smart radiator valves (see section further down), or think you might wish to do so in the future, you’ll also want to check whether your smart thermostat is compatible. Many will only support their own brand of smart radiator valves, so you may need to decide at this stage whether you’re happy to stick with this brand.

9. Check whether it comes with a connecting device

To actually control your smart thermostat, you’ll need to use a ‘connecting device’ (also known as a bridge or gateway). This plugs into your broadband modem and enables you to use the control app. Many manufacturers offer a starter pack that includes this, the thermostat itself and sometimes smart radiator valves also.

10. Read the reviews

It’s worth looking online for reviews about the reliability and user-friendliness of any devices you’re considering installing. This is particularly true because some of the flashier features that may draw you in – for example its ability to automatically learn your behaviour patterns – are said to be unreliable.

Which? has a guide to smart thermostats.

11. Consider getting it professionally installed

You may be able to install your smart thermostat yourself, as a like-for-like replacement of your existing heating controls. Some options will in fact describe themselves as ‘self-installed’.

However, you may want to get a qualified electrician or gas fitter, and for some models you will need to do so. The cost of installation is sometimes included in the smart thermostat price. For others, you’ll have to pay separately, so consider this when costing up.

Smart radiator valves

Smart radiator valves (SRVs, also known as smart radiator thermostats) can be used alongside a smart thermostat to control the temperature in individual rooms of your home. They’re therefore useful particularly for those with a larger house.

SRVs cost around £35-80 each, so it’s worth thinking carefully about which radiators you’d like them on. Here are some things to consider before choosing SRVs:

Are you tech savvy?

SRVs are a great way to control your heating, but they can be a bit complex if you’re not tech savvy. Luckily, you can add them to your heating system at any stage. If you don’t love tech, you may want to start by trying a smart thermostat and if you find this simple enough, adding SRVs at a later time. Just check that your smart thermostat is compatible with SRVs in case you do want to add them.

What features do you want?

Like a smart thermostat, you can control SRVs through your phone, tablet or laptop. You can use them to set different temperatures for different rooms (in degrees rather than the slightly confusing 0-5 scale on traditional valves). Alongside your smart thermostat, you can use them to create an automatic heating schedule. Some even have special features such as detecting and alerting you if a window is open in a heated room.

Decide what level of sophistication you want before buying. Which? has published an article on the best smart radiator valves.

Are they compatible with your smart thermostat?

If you want to buy SRVs from a different brand to your thermostat, you’ll need to check whether they’re compatible with your connecting device. Many connecting devices only support one brand. Unfortunately, this does mean that you are often ‘locked in’ to one manufacturer.

You can install them yourself

Unlike some smart thermostats, you do not need a professional to install smart radiator valves. The majority of SRVs will come with the correct adapter for most traditional valves. This means you can just remove your existing valve, fit the adapter, add your batteries to your new SRV and attach it to your radiator.

You’ll need the same connecting device as for your smart thermostat. If your thermostat is already installed, it will already be plugged in. If you’re doing it all at once, just plug the connecting device into your broadband modem. Then you’ll be ready to control your smart heating through your app.

What are smart tariffs?

Smart tariffs give you variable energy prices depending on supply and demand in the UK.

Like smart meters, they will not cut your emissions on their own. Nonetheless, smart tariffs are an important part of addressing our energy-related emissions across the country as a whole.

The amount of clean energy we have available in the UK will vary moment by moment.

While some traditional sources of energy – such as nuclear or fossil fuels – can run night and day, renewables tend to rely on certain conditions, such as it being windy or the sun being out. When the conditions are right, we might have a plentiful supply of renewables. At other times, however, if the weather is bad or everyone is watching the football, our green energy sources may not be enough. In these moments, the shortfall will be made up from nuclear or fossil fuels.

In order to transition to more clean energy, we will need to become more savvy about our energy use. Individual households can help with this. For example, if you have an electric car, you will want to charge when it’s windy or overnight when fewer people have energy needs.

A smart tariff will help you do this - and reward you for it – by telling you when energy prices are low. Low prices means that supply is outstripping demand, generally indicating the proportion from renewables is high at that time.

Do you need a smart tariff?

Smart tariffs are good for those who need a lot of energy but can be flexible about when they use it. They’re great if you have an electric car, heat pump, or battery.

Why is smart heating important?

The next ten years will be critical in mitigating the worst impacts of climate breakdown. By reducing our individual carbon footprints, we can help make change.

Our heating accounts for around 14% of our total emissions. About 77% of that is from homes, 14% commercial buildings and 9% public buildings.

When it comes to emissions from heating our homes, the first priority is reducing heating use. Smart heating is one great way to do this.

It's also important to consider the temperature of our homes. The Energy Savings Trust suggest 18C to 21C is suitable for most people and houses, and the NHS says that 18C is a comfortable temperature for most healthy and active people, but to have the house warmer if you are not very mobile, are 65 or over, or have a health condition. Turning the thermostat down just a degree or two can save money and carbon emissions.