Skip to main content

How do smart thermostats work?

Smart thermostats are quickly becoming a staple of the modern household, offering more versatility and control when compared to traditional thermostats. But how exactly do they work? And are there any disadvantages to upgrading to the fancy new technology? Here’s a closer look at how smart thermometers work, how they can streamline your heating and cooling needs, and how they can save you money.

How does a thermostat work?

Ecobee4 smart thermostat in a kids room.

Thermostats control how hot or cold your home gets. Before we explain the “smart” part of a smart thermostat, let’s look at the basics of thermostat operation.

Related Videos

Thermostats are built in one of two ways. Mechanical thermostats rely on the expansion of metal strips as the temperature rises and lowers. As the metal expands with heat, it completes an electrical circuit, which then activates your home cooling system. Similarly, your home heating can turn on when that strip gets cool, contracts, and activates a different circuit.

Digital thermostats operate under a similar mechanism. While metals physically expand with heat, they also reduce their ability to conduct electricity. Digital thermostats can accurately measure that change in conductivity with a special resistor and then activate or deactivate your home climate system accordingly.

What makes a thermostat smart?

Smart thermostats are able to communicate with more than just your home heating and cooling system. Common features include smartphone apps for remote control, internet connectivity to adjust for weather, and compatibility with voice assistants for hands-free activation. Over time, smart thermostats can learn the best time to heat and cool, which saves power by avoiding excessive usage and ultimately saves homeowners a little money on their monthly electric bills.

How do smart thermometers work?

Wyze Smart thermostat installed on wall being adjusted.

These extra functions require some additional hardware built into the thermostat. Smart thermostats require memory to store more information, antennae to communicate wirelessly, USB ports to communicate over a cable if need be, and a processor to handle input. This hardware will tend to be installed on a unified motherboard, similar to desktop computers. Smart thermostats typically require a common wire in the wall for power since they have many functions active in the background. The device also sports a lithium-ion battery in case of an outage or for preinstallation.

Displays will generally be higher quality on smart thermostats and integrate a touchscreen. Motion sensors are often included so the smart thermostat can detect if anyone is home and adjust the temperature of the house. Maintaining that comfort level is less necessary when nobody is home to trip the motion sensor. A microphone and speaker are sometimes present to enable voice assistants without needing to go through another device.

On the software side, mobile apps provide full remote control. Just download the app for your brand of smart thermostat from either the Google Play Store or the App Store, and follow the setup instructions. From here, you can usually set the target temperature, change presets, adjust the climate schedule, view usage history, and lots more.

Many smart thermostats are also expected to get Matter support in the coming year. This will allow them to interact with products outside of their normal ecosystem and give you additional control of your smart home. Google, for example, has already brought Matter to several devices and plans to extend its support to the Nest Thermostat in 2023.

What are the disadvantages of a smart thermostat?

The disadvantages of smart thermostats are few and far between. It used to be that cost created a significant barrier to entry, but now Amazon is offering smart thermostats for less than $100. The biggest challenge is education. Traditional thermostats only required users to turn a knob, but smart thermostats require additional setup and longer tutorials on how to take advantage of advanced functions (through apps, for example).

Older homes might also require a bit of rewiring if their current setup doesn’t include a C-wire, which can be a cumbersome process and could require a professional. Beyond those few drawbacks, there’s little reason to avoid upgrading to a smart thermostat.

Now that you know how smart thermostats work, you’re ready to start shopping for your first one.

Editors' Recommendations

What to do if your Amazon Alexa app is not working
Alexa app on phone.

Amazon Alexa might be one of the most popular smart assistants, but it’s not without a few flaws. For instance, some users have experienced crashes while using the Amazon Alexa app -- and others have found the app to be entirely unresponsive.

Issues like this are typically picked up on by Amazon and immediately fixed with a patch, but sometimes there’s an issue on the user’s end that needs to be remedied before things start functioning as intended. If your Amazon Alexa app is not working or responding, here are a few ways to fix it.
Check for a software update

Read more
The 6 best smart home products that support Matter
Amazon Fire TV on Echo Show 15.

Matter is arguably the biggest thing to happen to smart homes since their inception. The interoperability feature lets devices from different ecosystems interact with each other, giving you the freedom to shop for your favorite products regardless of manufacturer. Unfortunately, not all devices have rolled out support for Matter – and not all of them will.

Only a few notable products support Matter as of today, although dozens more are expected to add the functionality in the coming months. For now, here are the five best smart home products that support Matter. For a full list, head over to the official Matter website.

Read more
Do you need a subscription for a Ring doorbell or camera?
The Ring Video Doorbell 3 installed near a door.

If you’re in the market for a video doorbell, security camera, or another smart home gadget, you’ve probably already stumbled upon several products from Ring. The company is one of the most popular smart home brands, churning out reliable devices that are easy to use and easy to install.

You’ve also probably noticed that it offers a monthly subscription known as Ring Protect. But do you need a Ring Protect subscription to use Ring products? Or can they be used for free after installation? The company recently announced changes to a few of its Ring Protect plans, making them more valuable than ever before. Here’s a closer look at the service and whether you should sign up.
Do you need a subscription for Ring?

Read more