Smart Thermostats


While a smart thermostat itself doesn’t use much energy, it is an important part of an ENERGY STAR Home Upgrade because it controls equipment that uses a lot of energy for heating and cooling. Smart thermostats that earn the ENERGY STAR label are independently certified, based on actual field data, to save energy and save you money on your energy bills.

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For the average American household, almost half the annual energy bill goes to heating and cooling – more than $900 a year. Being smart about how you control your temperature settings will help you save money and stay comfortable in your home.  Make your energy choices count as we move to a clean energy future.

Why Choose An ENERGY STAR Certified Smart Thermostat Model?

A smart thermostat lets you control your home’s heating and cooling temperature settings from your smart device (phone, tablet, or computer). It uses a wireless connection, which allows you to control your home’s temperature and other features through an app.

Energy savings

To earn the ENERGY STAR, smart thermostat service providers must collect a full year’s worth of anonymized and aggregated real-world data from customers’ homes to make sure the product saves energy as it should.

Consider this: a smart thermostat unit itself doesn’t use a lot of energy, but it controls devices that use a lot of energy through heating and cooling. To demonstrate that the thermostat meets the energy saving criteria, smart thermostat manufacturers must show how the presence of their model reduces the HVAC system’s use in different climates across the country.

Only smart thermostats that earn the ENERGY STAR label have been independently certified, based on actual field data, to deliver energy savings. In addition, ENERGY STAR certified smart thermostats are required to be able to enter a low-power standby mode when inactive, which saves you even more energy!

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Count on ENERGY STAR to help you find a smart thermostat that meets your preferences and your budget, along with any rebates available in your area.

Find Products, Prices and Rebates

Some smart thermostats include more high-end features than others, meaning prices for smart thermostats can vary widely, ranging anywhere from $50-$300. Depending on where you live and your utility, there may be an opportunity to get an ENERGY STAR certified smart thermostat at a reduced price, either through a discount or rebate.  Use the ENERGY STAR Product Finder to review product features and enter your zip code to identify stores and prices in your area, as well as any available utility rebates.

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Before you invest in a smart thermostat, make sure it is compatible with your heating and/or cooling system and give some thought to the features you are most interested in. ENERGY STAR certified smart thermostats typically include features like learning capabilities, occupancy sensors and even voice assistant integration.

What To Consider Before Buying A Smart Thermostat


Before purchasing a smart thermostat, ensure the model you choose is compatible with your home’s HVAC system. Because of the variety of models and systems, you may benefit from consulting an expert before you buy. However, there are some easy checks you can do yourself.

HVAC System Type – Your home’s HVAC system will determine your ability to use a smart thermostat. Smart thermostats are compatible with most forced air HVAC systems that were installed after 1975. If you have an oil boiler or furnace, you may need an adapter. If your HVAC system is variable speed, multi-stage, or zoned for different areas of your home, you will likely need a professional to install a thermostat that can handle those systems. Most smart thermostats available in the U.S. market are not compatible with baseboard heating, biofuels, or in-wall heaters. That said, ENERGY STAR smart thermostats are compatible with most HVAC systems.

Wires and Voltage – If you remove your old thermostat cover and see thicker wires for line-voltage control, that is an indicator your HVAC system may not be compatible. Most smart thermostats use thin, low voltage wires. Unlike a programmable thermostat that can sustain itself from a battery, smart thermostats require more consistent and reliable power for things like keeping connection to your Wi-Fi network or the touch screen. Most, but not all, smart thermostats function by receiving power through a C-wire, or “Common Wire”. This provides a constant power source from your HVAC control board. Not having a C-wire does not necessarily mean you will be unable to have a smart thermostat, but it will likely influence the models and brands that will work for your home or may require an adaptor.

What Features You Should Consider When Choosing a Smart Thermostat

Each smart thermostat uses slightly different features to help homeowners save energy, so do your research, and choose the ENERGY STAR certified smart thermostat that's right for you.

Learning capabilities: Learns and adapts to your routine and your temperature preferences and automatically establishes a schedule that adjusts to energy-saving temperatures when you are asleep or away.

Geofencing: With your permission, your smart thermostat may use the app on your phone to detect when you are away or at home. When you leave the house and travel outside of a certain distance, the smart thermostat will lower the temperature (if in heat mode) or raise the temperature (if in cool mode). When you’re on your way home, the smart thermostat can automatically adjust your home’s temperature to your liking, so you arrive to a comfortable temperature.

Vacation mode: Lets the thermostat know when you will be gone from your home for longer periods of time to manage the temperature, avoiding frozen pipes in the winter and extreme heat in the summer.

Automatic updates: Updates software periodically to ensure it uses the latest algorithms and energy-saving features available.

Sensors: Helps to manage extreme temperature differences in a home through either temperature or occupancy sensing technology.

Temperature sensors work in single zone homes (meaning you have one HVAC system controlling the whole house) to monitor rooms with differing temperatures due to lack of insulation, sun exposure, etc. Sensors allow the smart thermostat to adjust the overall temperature to manage hot and cold spots, especially critical in larger homes.

Occupancy sensors work to determine which rooms are the most high-traffic and prioritize managing their temperature, without sacrificing comfort in the rest of the house.

Voice assistant integration: Some smart thermostats are compatible with popular voice assistant programs, meaning you can simply ask the thermostat to turn the temperature up or down a few degrees, among other things.

Music streaming: Some smart thermostats contain a speaker that let you stream music right from your thermostat.

Thermostat feature comparison

Ready to find the right smart thermostat for your home? The ENERGY STAR Product Finder can help!

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Once you’ve decided on which smart thermostat to buy, make sure it is properly installed. Depending on your personal comfort level, you may be able to install it yourself, or you may prefer to recruit the help of a professional.

Smart Thermostat Installation Tips

Find a Professional

If you need a second opinion on compatibility, or would prefer an expert’s help with installation, look for an experienced electrician or HVAC professional. The maker of the smart thermostat you purchased, or your electric utility should also be able to point you in the right direction. Some smart thermostat brands have trained staff available to guide you over the phone.

Location and Connectivity

For best performance, make sure your smart thermostat is reasonably close to the Wi-Fi router to prevent periodic disconnections. If your thermostat is too far from your router, consider a Wi-Fi range extender, which can improve overall connectivity.