What are smart thermostats and how do they work?

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Imagine you’re sitting at work on a late Monday afternoon in January and your boss has just said that everyone must stay late to finish the prep for tomorrow’s pitch. It starts snowing outside. The trains aren’t running properly.

By the time you finally leave the office and make it onto the bus you’re close to frozen. You’ve forgotten your gloves. You trudge home from the bus stop, put your key in the door and stroll into a toasty home. No one is home but you’re warming up nicely. How did this happen?

No, you aren’t a maniac who leaves their heating on full blast 24/7 (actually, if this is you then please read our tips to lower your energy bills), but you have a smart thermostat. As soon as you got the nod from your manager, you pushed the heating up at home via the app on your mobile phone. After the glove rage subsided you added a few degrees. It pretty much saved your day (especially after that bath you had too).

These beauties sound like the future, so what is the tech behind them and do you need one?

How do smart thermostats work?

Smart thermostats are a new piece of technology exciting the energy world. They connect your heating system to the internet, allowing you to control the temperature in your home (and other features) from your smartphone or another device when you’re out.

Yep, you’ll need internet connection to use it – that’s definitely non-negotiable. But wherever you are in the world it’s like you’re at home thanks to a smart thermostat.

They are different to smart meters – let’s just make that clear now. Smart meters show you how much energy your home is using in pounds and pence, in almost real-time, through an in-home digital display. They help you track what you use and understand where you can make reductions in your energy consumption.
Smart thermostats go further and give you complete control of your heating remotely. Awesome.

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They are comprised of three basic components. One part plugs directly into your heating, ventilation, and air conditioning (HVAC) system. This part communicates directly with the second part, which is the thermostat control itself. The third and final part is the smart thermostat app, which is downloaded to your smartphone, mobile device or computer.

Smart thermostats don’t just allow you to control the overall heating at home. These are among the other functions of higher-end models:

    • Multi-room control – Heating different parts of your home independently, although you’ll have to pay extra for smart thermostatic radiator valves to do so.
    • Hot water control – Usually only if you have a separate hot water tank, you can switch hot water off when you go on holiday and turn it back on before your flight home. No more waiting for it to heat back up when you’ve just got back from a long flight and need a warm bath more than anything else in the world.
    • Geofencing – Where technology is used to create a virtual boundary for a real geographical area, so it knows when you leave or return home and switches your heating on or off automatically, or asks you what you want to do.
    • Draught detection – Some models can detect if you’ve left a window open and even send you a notification to let you know.
    • Safety modes – Automatically limits energy consumption when you implement safety or holiday mode, only heating if your home drops below a safe limit to stop your pipes freezing in winter. If you’re the sort of person who can’t properly relax on holiday because you’re worrying about things like this, at least one of your problems is solved – you’ll be able to relax with a cocktail, at least until you think of something else you’ve forgotten.
    • Feedback on heating patterns – How many hours you’ve spent heating your home, compared against previous months. Gives guidance on energy-efficient settings too.

How to install a smart thermostat

Make sure your smart thermostat is compatible with your system and wiring before purchasing. Certain producers offer compatibility tools and checklists online to save you from buying the wrong one.

Otherwise, it’s a simple seven-step process:

  1. Turn off your HVAC system.
  2.  Remove the faceplate of your old thermostat.
  3.  Remove the thermostat wires from the backplate.
  4. Add a C-wire (if your system already has this then skip).
  5.  Use new thermostat’s backplate and pencil to mark the wall, drilling holes at the marks for the backplate screws.
  6.  Reconnect the wires once the new backplate is attached.
  7. Snap the faceplate of your new thermostat onto the backplate and turn on the breaker for your HVAC system.
  8. Connect the thermostat to Wi-Fi and get heating!

If any of these steps seem dangerous or you aren’t sure how to connect the wiring do get an electrician to help.

Do smart thermostats save you money?

Whether or not smart thermostats save you money completely depends on how you use them. If you use them smartly (see what we did there), limiting your energy consumption when you are out and on holiday, you’ll make savings over time.

But if you’re sitting on the sofa blasting extra heat every night to get you through winter, it’ll naturally set you back more. 

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They do come at a cost to buy, ranging from between £200-£300.

  • Hive from British Gas – £199 with installation.
  • Nest from Google – £249 with installation.
  • Connect from Scottish Power – £12.69 per month for two years, or you can reduce this by paying an upfront fee of £66 and then £9.94 per month. Includes installation but is only available to Scottish Power customers.
  • Tado – £199 purchase/£4.99 per month rental.
  • Evohome from Honeywell – £249 for base unit not including installation, £70 for each ‘smart zone’.
  • HeatMiser’s NeoKit2 – £265 with installation.
  • HeatSmart from EDF Energy – £199 including installation.

So which one is the best? Well, reviews from Trustedreviews.com, Expertreviews.com and Pocket-lint.com gave Evohome from Honeywell the best average score, because of its varied heating zones, clever dashboard and efficient learnings.

Time to switch

Had enough of paying through the nose for energy? Let us get you on the best deal possible to go with that killer smart thermostat. Just input your details and Look After My Bills will find you a host of options, which could save you up to £350. What are you waiting for?