How much can a smart thermostat really save?
Keep warm and save polar bears this winter
Here comes winter again, time to crank up that central heating. But if you’re using an old-fashioned manual thermostat, you could be burning a lot of money for no good reason.
A programmable thermostat differs from a regular thermostat in that you can set it to provide different levels of heat at different times or on different days. They’re generally a straight swap for your old one, and cost about £50. Fitting it should just be a matter of unscrewing the old one from the wall, and switching the two wires that control your boiler to the new device.
Having fitted one of these beasties, you now have full control over exactly how warm you want the house and when. That means you can have it automatically warm up in time for getting out of bed or home from work, and cool down to save money (and polar bears) when you’re not in or asleep.
Will it save money and/or the planet?
Yes, if you tell it to.
For example, having it automatically lower the temperature by 5º overnight when you’re safely tucked up in your duvet can save you about £15 over the course of the winter. Which doesn’t sound like a lot, but it’s money for nothing, and it would save about 70kg of CO2 emissions (or about 200kg if you use grid electricity for heating). It’s also a lot cheaper than fitting a more efficient boiler.
If you’re at work Mon-Fri you could save even more. Setting it to frost protection only for 7 hours a day could save you £80 and 335kg of CO2 over the winter compared to leaving the heating at 18º. And that still leaves plenty of time for it to warm back up before you get home.
So you can see that even if you’re heating your home really comfortably, using a smart thermostat to avoid heating it when you don’t have to can pay for itself easily. Sure, you could achieve some of the same savings by manually turning your stat up and down, but having it done automatically is much easier.
