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In an increasingly digitally connected world, it makes sense to use a smart thermostat to control your home heating and cooling. Smart thermostats can help you save money by learning your patterns and heating and cooling your home to a comfortable temperature throughout, without overdoing it. 

The trouble is finding the right one and knowing what to look for when selecting one. These are six of the most important things to consider when buying a smart thermostat. 

In this article: Google Nest Learning Thermostat, Honeywell Home T9 Wi-Fi Smart Thermostat and Ecobee3 Lite SmartThermostat.

HVAC system compatibility

Your smart thermostat must be compatible with your heating, ventilation and air conditioning system. Some only work with certain types of HVAC systems. For example, if you have a zoned HVAC system, your thermostat must be compatible with HVAC zoning. You’ll also find that some don’t work with two-stage heat pump systems, but there are plenty that do. 

C-wire requirements

Most newer heating systems use a common wire, or C-wire, to provide continuous power for features such as display screens and Wi-Fi. This is essential for most smart thermostats because it prevents Wi-Fi outages that disrupt service. If the thermostat you’re replacing doesn’t use a C-wire, you’ll either need to choose a smart thermostat with a C-wire adapter or get an electrician to install a C-wire for you. 

Ease of installation

Some smart thermostats are easy enough to install that you can do it yourself, while others require professional installation. You’ll often see manufacturers claiming that their thermostats are easy to install, but this really depends on your abilities. If you’re comfortable wiring a plug or a light switch, replacing your current thermostat with a smart one is easy. If the thought of this sends you into a cold sweat, call in a pro. 

Temperature and motion sensors

Some systems use multiple temperature sensors around the home. This prevents skewed results from a single temperature sensor sitting in a draft or a hot spot. Some also use motion sensors to tell when you’re getting up, moving around or leaving your home. This lets the system heat and cool your home more intelligently. For instance, it can turn the heat up when you get out of bed and down when you leave the house. 

Smart home system integration

If you already have a smart home system, it’s important to choose a thermostat that can integrate with it. While most can be controlled through an app, it’s nice to have them work with your smart home system, too, so you can use voice controls. This also lets your thermostat work with other smart devices. For example, if you have smart windows, your system can shut off the air conditioning when the windows are open. 

Automatic changeover

Thermostats with an automatic changeover function can switch themselves between heating and air conditioning. This is perfect if you live in a place where the temperature drops significantly at night compared to daytime. 

Best smart thermostats

Best Google Nest Learning Thermostat

Google Nest Thermostat

This thermostat works with 85% of HVAC systems, in most cases without a C-wire, unless you have a zone-controlled, heat pump, heating-only or cooling-only system. It knows when you leave the house, so it can help you save money by turning itself down, avoiding heating or cooling an empty home. 

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Best Google Nest Learning Thermostat

Google Nest Learning Thermostat

Although it costs more than the basic model, this updated Nest thermostat learns your patterns to heat and cool your home intelligently, saving more energy. Although it controls your HVAC system, based on what you like, you can also change things manually from anywhere, using an app. 

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Best Honeywell Home T9 Wi-Fi Smart Thermostat

Honeywell Home T9 Wi-Fi Smart Thermostat

Paired with sensors that know where people are in the home and the temperature in individual rooms, this thermostat can provide heat and air conditioning where you need it. You can set it up with most popular smart home systems for hands-free control using voice commands. 

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Best Honeywell Wireless Wi-Fi Thermostat

Honeywell Wireless Wi-Fi Thermostat

With a clear interface that’s easy to use, this programmable smart thermostat is a great choice for most HVAC systems. You can control it using Vera or Alexa smart home systems, as well as on the touchscreen and remotely, using an app on your smartphone or tablet. 

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Best Honeywell Home RTH9585WF Wi-Fi Smart Color Thermostat

Honeywell Home RTH9585WF Wi-Fi Smart Color Thermostat

Thanks to monthly reports and personalized tips, this thermostat can help you figure out where and how to save money on heating and cooling your home. With flexible programming options, you can easily tailor it to meet your needs.

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Best Ecobee Premium Smart Thermostat

Ecobee Premium Smart Thermostat 

Not only is this a smart thermostat, it also works as a smoke detector, monitors your home’s air quality and works in conjunction with some alarm systems. It comes with a smart speaker so you can use voice commands and play music through it. 

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Best Ecobee3 Lite SmartThermostat

Ecobee3 Lite SmartThermostat

If you like the look of the Ecobee Premium but don’t need all its features, the Lite is a pared-back version that just controls your HVAC system. It’s compatible with temperature sensors for best results and works with most smart home systems. 

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Best Amazon Smart Thermostat

Amazon Smart Thermostat

Easy to pair with Amazon Alexa devices, this is a solid addition to your smart home system. It can program your heating and cooling to keep you comfortable without effort. 

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Best Wyze Programmable Smart Wi-Fi Thermostat

Wyze Programmable Smart Wi-Fi Thermostat

This basic smart thermostat lets you control your home’s temperature from an app and create schedules, and works with most smart home systems. It requires a C-wire but comes with a C-wire adapter, which is great for systems that don’t already have one.

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Best Emerson Sensi Touch Smart Thermostat

Emerson Sensi Touch Smart Thermostat

For buyers who like the idea of a smart thermostat but are concerned about privacy, Emerson states that it won’t sell your information to third parties. It’s easy to install, though it requires a C-wire, and is simple to integrate with most smart home systems. 

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Lauren Corona writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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