smart thermostat guide

Smart Thermostat Guide

While having new radiators is one way to having an efficient home heating system, a smart thermostat takes it to the next level.

You may have heard or seen smart thermostats when looking online or even speaking to a plumber while getting your radiators checked. They are the most modern way of ensuring your heating is warm where and when you want it as well as for saving money.

But what are smart thermostats? Well, Plumbworld is here to explain everything about them - how they work, why you should consider buying one, the benefits and the installation process. This guide will help you learn more about smart thermostats before buying.

Read on to find out more about smart thermostats and their benefits...

What are smart thermostats? 

what are smart thermostats?

Smart thermostats are a new trend in home heating to save money on your bills. They can switch your heating on or off remotely via an internet connection. So, you can use your smartphone or a tablet to turn your heating on when you're on you’re close to home. 

Not only can you set the heating remotely, but many of these digital heating systems can show you how much heat you’re using - monitoring your usage and learning your routine.

It’s important to remember that these aren’t smart meters. Most energy firms are offering to install those for free. Unlike smart meters, you can install or arrange installation of smart thermostats yourself. This means it doesn't matter who supplies your energy. Plus, smart thermostats don't affect switching suppliers.

How are smart thermostats different?

As the name suggests, they're smarter versions of thermostat than your old manual model. On a basic level, they’re the same. Like all thermostats, you can programme a schedule to suit your needs, or boost the heat if you're feeling the cold and turn it off when you want.

Read more: Essential Heating Tips and Checks Before Autumn

However, it’s beyond this where the differences emerge with smart thermostats because of their additional technology. They have more functions, such as learning how your home heats up, what temperatures you like, and detecting open windows or draughts.

Some smart thermostats can even keep track of when you leave the house or if you're coming home. It’ll then adjust the heating for you or make sure your pipes don't freeze while you're on holiday or out and about on a cold day.

How much do smart thermostats cost?

how much do smart thermostats cost?

Smart thermostats can often cost anywhere between £150 and £280, depending on the make and model. A Honeywell Home Lyric T6 at Plumbworld, for example, costs around £130. Most manufacturers will also offer professional installation which can add about £50 - £100 to the cost, but some can be easy to fit yourself with installation instructions.

How do smart thermostats work?

how do smart thermostats work?

Smart thermostats are intelligent and connect to both your boiler – via existing thermostat wired connection – and your home Wi-Fi network. This means that your old boiler can be part of the smart home. Of course, your boiler needs to be compatible. You’ll need to check this with the manufacturer when you are choosing your smart thermostat.

Read more: Heating Advice: How to Check Your Radiators

Now, with the simple download of an app, you can alter your thermostat settings from wherever you are at the touch of a screen.

To change the temperature while you’re out, you would, for most smart thermostats:

  1. Open the smartphone app and set the temperature
  2. The new setting is sent to your home
  3. Your Wi-Fi router transmits the new instruction to your thermostat
  4. Your smart thermostat readjusts the temperature and sends a signal to your boiler to turn on or off

Tip: If you do get a smart thermostat, you should make sure you take the appropriate security precautions. This can include choosing a secure password, just like you would for your WiFi.

Will a smart thermostat still work if my internet goes down?

If your internet goes down, don't worry. Your heating will stay on and your smart thermostat system should continue to run the schedule you’ve logged into it. You may not be able to control the thermostat with your app or online, but you can still use the manual controls on the thermostat itself if needed.

Smart thermostat features to look out for when buying

Hot water control 

Some smart thermostats can control your hot water, as well as your central heating. If you have a combi boiler which provides hot water instantly, then you won't need a smart thermostat that does this. 

Note: Not all smart thermostats with hot water control include it as standard. 

Being able to use an app makes turning on the hot water, like your heating, much more convenient. If you've been away for a few days and switched it off, and fancy a hot shower, simply use your smartphone to turn it on again before you get home. 

Like a traditional thermostat, you can program a schedule. This ensures that you don't suffer a cold shower in the morning because you forgot to put the hot water on but you can use your phone, a tablet or your computer.  

App and PC functionality 

Many smart thermostats can only be controlled by an app and may not have a standard website that can be accessed from a computer.  If you don't have a smartphone, you'll need a thermostat that also has website controls. 

Multi-room control or zonal heating 

Some smart thermostats allow you to set individual temperatures for different parts of your home from the same smartphone app or computer. This is particularly useful if you have a larger home, where some rooms aren’t being used as much. 

So, if you are usually spending the evening in the living room, you can keep it nice and cosy while turning the heating down in any rooms you're not using. To do so, you may have to buy either an extra thermostat or another device for each area you want to use different settings for. These aren't always cheap, some can cost as much as the first thermostat. 

Note: You'll often need an existing multi-zone heating system to be able to do this. You may also need to look for smart thermostatic radiator valves.

smart thermostat features


Smart thermostats can adjust the temperature according to the weather forecast and the temperature outside. So, if a cold snap is on the way, the thermostat can adjust your temperature settings to reflect the fact that there’s about to be a change. 

Motion sensors & GPS tracking 

These features detect when you enter and leave your home and adjust the heat settings accordingly - part of a smart thermostat’s learning feature. The thermostat will turn the heating down when you've left and pre-heat your home when you're on your way back. 

Motion sensors and GPS are most useful if you're in and out of your house at irregular times. Otherwise, you can rely on the scheduled temperature settings to turn the heating off when you leave and back on for your return home.

How to install a smart thermostat

Obviously, the instructions are basic and a guide - you will always have instructions provided by the manufacturer that comes with your new smart thermostat.

  1. Turn off the power: you must always turn off the electric power before doing any DIY job that involves electricity.
  2. Open the old thermostat: take the front face of your current unit off - this may require unscrewing.
  3. Label the wires: next, you need to label the wires from your old thermostat - letters
  4. next to the terminals where the wires are inserted. Use whatever you can to label all of the wires. Most thermostats will only have four wires, but you may have more, so label everything. You could even take a photo instead.
  5. Take the old thermostat off: now it’s time to unscrew the old thermostat and carefully take it off the wall. Use your screwdriver and it should come off fairly easily. Make sure not to take the wires with you.
  6. Hang the new thermostat: use a level to make sure you’re screwing the thermostat on the wall correctly. After you mark the wall, add the plastic encasing that goes around the device and hang it using the markings you made.
  7. Attach wires to the new thermostat: match each wire to its terminal and connect them. Pull each wire to make sure they’re secure.
  8. Turn the electricity back on: turn the power back on and check if there is a start-up screen on your new thermostat. If not, turn the electricity off and recheck the wiring to make sure they’re in the right spots and secure.

Can smart thermostats help me save money?

can smart thermostats help save me money?

How much money you can save with a smart thermostat all depends on your habits. We’ve picked out some key habits that will see a smart thermostat work best:

  • If you want to be able to see exactly how much heating you’re using and want to make lifestyle changes. 
  • If you're tech-savvy, use a smartphone or computer regularly and are comfortable using apps.
  • Those with a busier lifestyle who want to be able to programme a thermostat on the go. 
  • If you have a regular routine, smart heating controls can learn it and ensure your home is warm when it needs to be. 
  • If you are likely to stay in the same property for several years, you can recoup the cost of installation through energy savings.
  • If you don’t have a routine - i.e. you may come home at different times of the day and want to control the heating to reflect this rather than a set schedule.

Now that you know more about smart thermostats, why not look at our range of other innovative products, such as boiling water taps, smart radiators, smart showers, bathroom wall panels, and toilet and basin combination units.

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