Best smart thermostats that don't need a C

Mar 27, 2024

No C-wire, no worries; these smart thermostats will still work in your home

The adventure of upgrading from a traditional thermostat to a smart thermostat is both fun and a great place to begin creating your smart home setup. The thermostats in this list are energy efficient, make it easy to control your home's temperature (even when you're away on vacation), and offer many great features.

Smart thermostats typically allow you to set up a usage schedule to keep your home at a comfortable temperature. Some offer specific usage modes, while others can learn your current usage habits and adapt them to help you save energy or even automatically turn on or off when you exit your home's Wi-Fi network. With all these great features and the ability to control them from your phone or a compatible smart home speaker, we're sure you'll find the perfect smart thermostat for your home — without worrying about having a C-wire.

Feature-rich and easy to use

If you're in the market for a simple yet powerful smart thermostat, you can't go wrong with the Lux GEO-WH Wi-Fi Thermostat. It comes in a variety of colors, it's rich with features that'll help save money on your monthly energy bill, and it's easy to set up and use.

The Lux GEO-WH Wi-Fi Thermostat is easy to install, energy-efficient, and gives you multiple power options (2 AA batteries, microUSB, or system power), which is precisely why it's our best overall pick. It offers a stylish design and comes in two colorways: black with black chrome accents or pearl white with brushed chrome accents. You also have vertical or horizontal mounting options to suit your home's style, and everything you need for installation ships with it. In addition, the physical device interface and its companion mobile app are also incredibly intuitive and easy to use.

The Lux GEO-WH offers seven-day programming and an air filter monitor. It will also automatically adjust your home's temperature with its handy geofencing feature to ensure a comfortable temperature when you're there and adjusts to a more energy-efficient level when you're not there. The thermostat is compatible with nearly all conventional HVAC systems — as well as Alexa and Google Assistant — and features a large backlit display. The Lux GEO-WH Wi-Fi Thermostat is a powerful, flexible, and excellent option for your smart home.

Learns and adapts efficiently

The gorgeous Google Nest Learning Thermostat automatically tailors its performance to your unique temperature preferences, ensuring your home is always at the optimal comfy temperature. It also adjusts itself when you leave to save you money and has an intuitive mobile app.

If you've got a few extra bucks to spare, you can't go wrong with the powerful and clever Nest Learning Thermostat from Google. It is the most capable and advanced smart thermostat on the market, with perks that are hard to compete with. For example, the thermostat's auto-schedule feature learns your home's unique temperature preferences over roughly one week and tailors its operation thusly, so you won't have to fuss over scheduling.

Another feature — Home/Away Assist — notes when you leave your home's geofence and automatically adjusts the temperature to an energy-efficient setting (this way, you aren't paying to heat or cool your house when you aren't there). The Nest Learning Thermostat will also display a leaf icon on its interface when you choose an energy-saving temperature. The app lets you manage the temperature, review usage history, and tweak the auto-schedule.

Since it's compatible with Alexa and Google Assistant, you can also control it via voice commands if desired. The thermostat is compatible with 95% of existing heating and cooling systems, plus setup takes just 30 minutes or less. It even comes in a variety of colors — stainless steel, black, copper, mirror black, white, and polished steel, so it'll match your home decor.

Affordable yet robust functionality

The Wyze Smart Thermostat is a frills-free yet solid thermostat with a nice array of easy-to-use features. It includes a C-wire adapter, offers robust integrations, and makes setup a cinch.

Not only is Wyze's stylish Smart Thermostat one of the most affordable options out there, but it also makes quick work of setup; its companion mobile app offers step-by-step instructions to guide you through installation and configuration. And although the thermostat does not require a C-wire for installation, it includes an adapter in the box that you'll need to factor into your setup.

The thermostat can be controlled from its physical interface via Alexa or Google Assistant and also through its mobile app. On the app, you can set up a schedule for up to seven days at a time and monitor or adjust the temperature in your home. The app will also track your usage and provide customized insights to help you optimize use and save energy, such as turning off the heat while you sleep or opening a window at night instead of cooling.

Great design, even better features

The Google Nest Thermostat offers quick and easy installation, a modern design in four colors, and seamless smart home integration. It also puts intuitive controls and usage history reports at your fingertips and will even alert you when it's time to change your air filter.

Want a thermostat that's just as powerful and feature-rich as it is attractive? The Google Nest Thermostat offers a gorgeous modern design in four colors: Charcoal, Fog, Sand, and Snow. It boasts a lengthy list of great features and helps warm and cool your home year-round while optimizing energy usage.

The Nest Thermostat is designed to work without a C-wire in most heating and cooling systems but has a Power Connector bundle option available for seamless DIY installation. It supports dual-band Wi-Fi and will alert you through the mobile companion app when it's time to replace your air filter or if an issue is detected. In addition, you can control the thermostat manually on the device via Alexa or Google Assistant voice commands and through the mobile app.

The app walks you through the 30-minute setup and makes it easy to control the temperature, set a schedule, and view usage history. It'll send you suggestions via the Savings Finder feature, which can help you save money by tweaking your programmed schedule. Its built-in motion and proximity sensors note when you're home and keep it at your preferred set temperature. Likewise, it'll note when you leave and then automatically adjust your home's temperature to a more energy-efficient setting.

Simple whole-home functionality

If you're looking to control the temperature in a specific room in your house, the Honeywell Home T9 Smart Thermostat can help you do just that and more. It's loaded with a variety of energy-efficient settings to help you save money, especially when you're away from home. Plus, it's easy to install and includes a C-wire adapter in the box.

The Honeywell Home T9 Smart Thermostat is an outstanding pick for any home. It's an especially genius choice if you're looking for granular temperature control for one or more specific rooms in your house. It's designed to work with Honeywell's Smart Room Sensors (not included in the box), which you can place in any room of your house. Then, you can select a temperature for each room, and the Home T9 will work to average that out overall.

You can manually adjust a room's temperature from the app, create a custom schedule, or tell the system to prioritize achieving a temperature for a specific room. The thermostat features Auto Home and Away modes, which use geofencing to automatically adjust your home's temperature to one that's more energy efficient while you're away. It's also Energy Star certified, so it can track your usage and send you monthly reports with personalized efficiency tips. Note that the Home T9 does require an adapter for setup in homes without a C-wire, but there is a bundle you can select that includes an adapter in the box.

Easy setup

With the Ecobee3 Lite Smart Thermostat, you'll enjoy a simple setup, an intuitive and easy-to-use interface (and app), and eco-friendly performance. You also have the option to snag compatible sensors and expand the functionality of this incredible smart thermostat.

New to the whole smart home thing? Stay simple with the Ecobee3 Lite Smart Thermostat. It works with Alexa, Google, Apple, IFTTT, and Samsung SmartThings, so it'll work with whatever smart home ecosystem you use. Its all-digital display will look great in any home but note that while this design is stylish, having no physical buttons to work with might make things frustrating if the software unexpectedly seizes up.

Despite that, the Ecobee3 Lite is super easy, relatively quick to set up (under 45 minutes), and includes a power extender kit right in the box so that it can be powered without a C-wire. It also offers a wide array of energy-saving features designed to help you optimize usage and save a little extra cash on your monthly energy bill. For example, it will automatically adjust the temperature during peak hours, in high or low humidity scenarios, when you're away from the house, and can even pre-cool any time when it isn't peak rate time.

If you're interested in getting some SmartSensors and signing up for Ecobee's Smart Security subscription (which starts at $5 per month), you can also take advantage of the clever pause function. This automatically shuts off your air conditioning if the sensors detect you've left a door or window open for over five minutes, which is a great way to potentially save some dough on your summertime energy bills.

Functionality over fashion

The Emerson Sensi Smart Thermostat may have a dated design, but it's a solid option for anyone wanting a more basic thermostat for their smart home. It boasts easy installation, great integration, and even alerts you about regular maintenance.

Smart home gadgets are a ton of fun, but it can be overwhelming to keep track of them all and remember how they work. If that's the case, we heartily recommend the Emerson Sensi Smart Thermostat. It has all the basic features you could want from a smart thermostat, and it looks like a classic one for those who prefer that look. The plain (albeit a bit dated) design focuses on putting functionality at your fingertips, instead of being buried under tons of complicated menus or a fancy app design.

Emerson Sensi offers a great array of smart features that you can tinker with even when you're away from home, whether at work, on vacation, or just grocery shopping. Installation is easy; you can do it yourself as it features a built-in level and is compatible with most HVAC systems, Alexa, Google Assistant, Apple HomeKit, and Samsung SmartThings.

The companion mobile app makes it easy to set, change, and program the thermostat's run schedule no matter where you are, as built-in sensors can detect and alert you to extreme temperatures and humidity levels in your home. The thermostat also monitors your HVAC system and sends you regular usage reports, equipment alerts, and maintenance reminders for changing your filters regularly.

Simple and modern sensor-based controls

With Levoit's Aura Smart Thermostat, you can connect up to 16 Levoit sensors for more granular control over your home's temperature. It also rocks a bold modern design and offers daily reports and tips for efficient usage.

Want a simple, modern, and affordable thermostat that plays nice with external sensors? Then, you can't go wrong with Levoit's Aura Smart Thermostat. This device offers a nice array of smart features, a gorgeous and engaging design, and a powerful app. It also does its best work with a few sensors set up around your house, making it a solid choice if you want to have sensors.

The Aura sports a bright 4-inch display that makes it easy to see a bunch of information at a glance, like the current temperature and humidity levels in your home, today's weather, and which mode it's set in. From that same screen, you can quickly adjust the temperature and tap to open its menu to tinker and other settings.

You can also access and control the thermostat through its companion mobile app and via either Amazon Alexa or Google Assistant. The app makes quick work of setting up a schedule and can also send you daily usage reports that include tips for more energy-efficient usage. You can also connect up to 16 compatible sensors (sold separately), which allow you to monitor the temperature in different rooms and even tailor your home's overall temperature for a specific room.

Trustworthy, affordable, and ultra-basic

Want an easy-to-use smart thermostat from a reliable brand designed to help you save money each month? You can't go wrong with the GE Cync Smart Thermostat and its sensor-compatible functionality.

When it comes to home appliances, GE is a long-trusted brand. So, it's no surprise that it offers a great thermostat option, the GE Cync Smart Thermostat. This thermostat pairs robust usage reports aimed at saving you money with wide HVAC system support and compatibility with external sensors, all backed by a trusted brand name.

The GE Cync thermostat comes with everything you need for a quick and simple setup in the box. It even has a built-in level on the interior that helps ensure you don't install it askew and is compatible with most HVAC systems. However, it requires a power extender kit for those without a C-wire. It can also be paired with a compatible sensor that you can place in another room if you want to have the system tailor operate to one specific area rather than your whole home.

The thermostat can be controlled by voice via Alexa or Google Assistant or through the mobile app. On the app, you can also program a schedule to ensure your home is at a comfy temperature when you wake up, come home from work, and go to bed. In addition, the app includes an eco-mode to help you save money on your monthly energy bill year-round. It also works with any of GE's other Cync smart home products.

Perfect for Alexa fans

Despite its limited integration, the Amazon Smart Thermostat offers powerful functionality, including the auto-programming Hunches feature. It also has an attractive modern design and an in-app installation guide that's a cinch to follow for DIY setup.

If you're deeply embedded within the Alexa smart home ecosystem or want to be, you've got to go with the Amazon Smart Thermostat. The sleek device makes upgrading from a traditional thermostat a cinch, especially since the companion Alexa app can guide you through installation.

Amazon emails you once you've purchased the thermostat to alert you to any rebates offered by local energy companies available for enrollment. The thermostat is also Energy Star certified, which means you can conserve energy and save money on your energy bill. It also tracks your usage and displays it for you with clearly-labeled charts. Moreover, the trainable Hunches feature allows Alexa to automatically adjust your thermostat when you're asleep or not at home and slowly build that into an auto-programmed schedule.

The thermostat's clean, minimal design blends in with any home. Plus, its simple, stripped-down interface is easy enough for anyone to understand — it only shows the current temperature, up and down arrows for changing the temperature, and a select/mode button. Otherwise, all other functionality is available via the Ring or Alexa apps.

Adding a smart thermostat to your home is a great idea, and even if your HVAC system does not have a C-wire, any of the options in our lineup will work anyway and put all that fantastic smart functionality at your fingertips. Our best overall pick, the Lux GEO-WH Wi-Fi Thermostat, offers multiple power options, colorways, and mounting options. It also sports a geofencing feature for energy efficiency, monitors your air filter, and works with both Alexa and Google Assistant.

If you've got a few extra bucks in your budget, we heartily recommend springing for the fantastic Google Nest Learning Thermostat. This immensely powerful smart thermostat learns and adapts to your home's unique temperature preferences and usage patterns, then automatically creates a tailored schedule to run on. It's also flush with other great features, like Home/Away Assist, so you'll never be paying to heat your home when you aren't there. Its incredibly intuitive design and feature-rich app make it easy to control your home's temperature, view usage history, and receive maintenance reminders from anywhere.

And if you're looking for a budget-friendly option, the affordable yet impressive Wyze Smart Thermostat is hard to beat. For a fraction of the cost of most other smart thermostats on the market, this one offers a slick design, solid integration options, a step-by-step installation guide in the app, and an adapter that allows it to work with any HVAC system, including those without a C-wire. No matter your budget or the features you're looking for, we're certain that one of our top picks will be an amazing addition to your smart home.

While most homes have a C-wire, some (especially older houses) do not. The C-wire, also called a common wire, connects continuous power from your heating and cooling system to your thermostat. If your home does not have one, don't fret — plenty of smart thermostat options (like the ones in our list above) will work without one. They are typically powered by other means, like batteries, an adapter, or a power extender kit. Compared to "standard" thermostats, they aren't too different to set up. You can easily install them yourself or hire a professional to install.

Smart thermostats make it easy to control your home's temperature from the device itself or its companion mobile app (even if you're out of the house). You can also program a schedule for them to run on, helping to ensure that your house is at a cozy temperature when you wake up and at a more energy-efficient level during peak hours or when you're not home. Some can even learn your typical usage patterns and adapt your schedule for improved efficiency. Others work with separate sensors you can place around your home, ensuring that those specific rooms get heated or cooled to a specified temperature.

Powerful, feature-rich, and easy to use

If you're in the market for a simple yet powerful smart thermostat, you can't go wrong with the Lux GEO-WH Wi-Fi Thermostat. It comes in a variety of colors, is easy to set up and use, and is rich with convenient features that'll help save money on your monthly energy bill.

Suzanne has over seven years of experience researching, testing, writing, and editing articles about all kinds of tech, from smart home gadgets and EVs, to Android apps and nerdy media. She graduated in 2015 with a Bachelor’s Degree in English Language and Literature and a minor in Professional and Technical Writing. Since then, she has spent her professional time writing and editing articles about consumer technology at publications like Top Ten Reviews, Active Junky, Review Geek, and LifeSavvy. When she’s not working, Suzanne enjoys reading, gaming, cooking, hiking, and going on road trips.