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.
Image used with permission by copyright holder

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.

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.
Wyze / Wyze

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.

Simon Sage
Simon has been publishing in tech since before the first iPhone was released. When he's not busy lighting a candle for the…
Best Nest thermostat deals: New and refurbished starting at $35
amazon slashes prices on google nest smart thermostats for black friday thermostat e 1

One way to save some money while modernizing your home is with things like refrigerator deals, oven deals, and appliance package deals. But if you’re hoping to feel a little more futuristic throughout the home you should take a look at what the Google Nest Thermostat lineup has to offer. There are a number of different thermostat models available, each adding some modern smarts to keeping your home at the right temperature. The Nest Thermostat lineup is also a good one to turn to for some savings, which is why we’ve rounded up all of the best Nest Thermostat deals available right now. You’ll find those below, and if you’re looking for some other ways to expand, upgrade, or start from scratch with your smart home setup you should also check out all of the router deals and security camera deals available right now.
Google Nest Temperature Sensor — $34, was $39

The Google Nest Temperature Sensor is a great device to add to your home if you already have a Google Nest Thermostat. Most homes aren’t the same temperature in every room, and Nest Temperature Sensor can communicate with a Nest Thermostat which rooms should be a certain temperature at different times throughout the day. All you have to do is place it on a shelf or on the wall. You can also add multiple Google Nest Temperature Sensors throughout your home to create an efficient heating and cooling network.

Read more
Ecovacs Deebot X2 Combo vs. Dreame X40 Ultra: Which robot vacuum is best for your smart home?
The Ecovacs X2 Combo installed in a home.

The Dreame X40 Ultra and Ecovacs Deebot X2 Combo are both well-rounded robot vacuums. They bring heaps of functionality to your home, including self-cleaning docks, robots that can both mop and clean in a single run, and luxurious designs that blend with most home décor. All that doesn't come cheap, and you'll be spending well over $1,000 to get your hands on either robot. That means you'll want to carefully weigh your options before making such a hefty investment.

From vacuuming and mopping performance to pricing and additional features, here's a look at the Ecovacs Deebot X2 Combo and Dreame X40 Ultra to help you decide which is best for your home.
Pricing and availability

Read more
Is a smart air purifier a wise investment?
Coway Airmega IconS True HEPA air purifier in home

Spring is in full swing, and much of the population has officially succumbed to the sniffling and sneezing associated with seasonal allergies. that makes now a great time to consider picking up an air purifier, as they're shown to do wonders for air quality. Along with handling dander from pets, they'll also eliminate pollen and other allergens that may wander through your doors and windows. Air purifiers are incredibly popular -- and smart air purifiers are finally starting to catch up.

But should you invest in a smart air purifier, or are you better off with a traditional one? Here's a look at these unique gadgets to help you decide if one is right for your home.
What is a smart air purifier?

Read more