Honeywell Home X8S Smart Thermostat Review

About Honeywell Home X8S Smart Thermostat

• Price: $219.99 (or $249.99 with room sensor)
• Type: Smart
• Compatibility: Works with up to 3 heat/2 cool heat pump with electric backup or 2 heat/2 cool conventional systems, hot water heat, forced air (gas, oil, or electric)
• Power and connectivity: Corded electric, C-wire required, Wi-Fi 2.4 or 5.0 GHz (802.11ax/ac/a/b/g/n)
• Smart home capability: Google, Alexa, Apple Home, Matter
• App: First Alert by Resideo
• Dimensions: 0.96 inches x 5.24 inches x 3.54 inches
• Weight: 0.91 pounds
• Color: White or black
• Includes in package: Smart thermostat, UWP wall plate; screws and anchors; booklet

How we tested

While other tech journalists may have a different approach, my process of reviewing products aims to mirror the real-world user experience: I set up and use the gear without any assistance from the manufacturer or public relations agency.

As such, the Honeywell Home X8S Smart Thermostat was unboxed, along with its optional wall plate and small installation pamphlet. As with our review for the Honeywell Home X2S Smart Thermostat, I simply replaced one of the thermostats on my wall that works with the X8S and its dual 8-pin vertical alignment on the back, already with wires connected for power.

Otherwise, also in the box is a sheet with a QR code to receive a free C-Wire adaptor from Honeywell Home—if you don’t have the required C-Wire to connect the new thermostat.

Once on the wall, you have a choice to set up the thermostat via the app or by following along with the on-screen instructions. Either way, you join the thermostat to your Wi-Fi network, sync it with the free First Alert by Resideo app (iOS, Android), and then give the location a name for easy access.

Problem is, the Honeywell Home X8S wasn’t listed among all of the thermostats in the app. I also searched for “X8S” in the First Alert search window. No dice.

Alas, I had to call Honeywell Home support, and after some back-and-forth, I was advised to try one of the last options, ambiguously named “denali_device_name_x12_x11_trade.” It worked, but an unnecessarily frustrating way to start the review. See the “What we don’t like” section below for more on app issues.

Once up and running, though, the experience was much, much smoother.

What we like

It features a redesigned look and user interface

The Honeywell Home X8S proved to be a comprehensive offering for homeowners, rivaling many of the bigger names in this space. Taste is subjective, of course. The Google Nest and Ecobee thermostats are quite slick, while most Honeywell Home products look, well, more “old school,” let’s say.

More attractive than its predecessors, the X8S is nestled somewhere in the middle, with a more modern and appealing design than previous models, with rounded edges, and a large 5-inch touchscreen that’s both good-looking and functional.

With various color and style options to choose from, the large display prominently displays the temperature, as well as time (digitally, or as an analog clock), humidity, indoor air quality, and other info you can add to the main dashboard (see below). I kept the default setting for the screen to illuminate when walking up to it, which is handy. Settings and preferences can be adjusted on the thermostat itself or via the First Alert app.

Like most other smart thermostats, many functions can also be controlled with your voice via a smart speaker (supporting Google, Alexa, and Siri).

A thermostat’s accuracy and feature set are arguably more important than its looks—and thankfully, it did indeed excel in its performance, as you’ll see in the next section.

It offers advanced features and motion sensors

The Honeywell Home X8S is a feature-rich smart thermostat that offers much more than standard temperature control.

It works seamlessly with most HVAC systems, such as furnaces, air conditioners, and heat pumps, to enhance your home comfort. You can set it to decide when to turn heat or A/C on and off and automatically adjust temperature based on whether anyone is home or not; set daily or weekly schedules (such as cooling down the home every weekday at 9pm for a better night’s rest); read info about indoor humidity and indoor air quality (IAQ); and receive reminders to wash or change the air filter.

You can choose to display “feels like” temperature that factors in both the ambient air temperature and the indoor relative humidity to calculate a perceived comfort level—similar to how weather reports use the heat index or wind chill. Smart. In other words, this opt-in feature is designed to ensure that when you set the thermostat to a specific temperature, it is the temperature you actually experience, not just the raw air temperature reading.

Despite some issues upon setup, the First Alert by Resideo app worked well, allowing you to see info and make changes—even when away from home.

With a smart speaker, say something like “Alexa, raise the temperature by three degrees” or simply “Siri, make it warmer.” Or you can say, “Hey Google, what's the temperature inside”? This is ideal for those who may have dexterity challenges or mobility issues.

This smart thermostat also supports Matter, an increasingly popular standard for smart home devices, which are easier to set up (QR code, numerical code matching). They work seamlessly together with other products (regardless of the brand or ecosystem) and generally offer faster response times, better reliability, and security.

Missing in the Honeywell Home X2S, which I also reviewed, the X8S does support small occupancy sensors to place in various rooms, for more precise comfort. This lets you prioritize living areas by day and bedrooms by night. Sensors have an extended range of up to 200 feet and are self-standing or can be adhered to a wall. Not only could these devices raise or decrease the temp in the room to better serve its occupants, but they can also automatically reduce energy use by detecting when a room (or the entire home) is empty. It was easy to pair the sensor to the thermostat, and it seemed to accurately provide a reading of that room’s temperature (I purposely moved it to a cooler room in the basement at one point, and it accurately dropped the temp).

In fact, the model I reviewed includes a sensor (for $249) to be purchased separately. You can even add up to 20 sensors in one home, if desired.

It features smart home integration

Resideo made a big deal about this thermostat supporting some wireless doorbells: the First Alert VX1 and Ring-branded doorbells. Once paired, when someone rings the compatible doorbell outside, you can see and talk to them from the thermostat—just like the smartphone app for these products.

It worked, yes, as the X8S was paired with our Ring wireless doorbell, but the quality of the stream wasn’t as clear or smooth on the thermostat screen as it is on the app. Also, depending on where you keep your thermostat in the home, it may not be an ideal place to talk with someone at your front door. For example, I’d argue most people have their thermostat mounted to their wall in a hallway (or maybe in a family room), but it may not be a place you’d typically talk on an intercom with someone at your front door.

And so, I’d call it a “nice to have” feature and not a “need to have.” Plus, you can’t access a live stream outside via the thermostat anytime you want—only when someone activates the doorbell.

What we don’t like

We experienced setup woes right out of the box

As alluded to earlier, the name of the thermostat isn’t even listed in the First Alert by Resideo app. Read that again. And so how are you supposed to set up the thermostat, unless you opt to do so on the thermostat’s screen itself and disregard half of the functionality the app offers?

I had to call Resideo support on a Saturday—thankfully, they were open—and even the tech support person had to look up how to pair this. We first tried “denali_device_name_x12_x11_retail,” which didn’t work, but the last option did, named “denali_device_name_x12_x11_trade.” Not sure how anyone could figure this out on their own. Even as someone who is quite tech-literate, I had to call to ask why the X8S isn’t listed as an option. The thermostat debuted a couple of months ago, in December 2025, so there is no excuse.

It's difficult to pair with a doorbell

While the feature worked—you can see and talk to whoever is at your front door via the X8S—it was challenging to find and enable this doorbell feature to begin with.

If you click on the “Devices & Sensors” icon on the thermostat, you can only add another room sensor. On the app, if you tap “Devices,” it only lists the thermostat(s) you have or other smart home products supported by the First Alert app—and Ring isn’t listed here (only a doorbell called the VX1 HD Video Doorbell).

Instead, you need to launch the app, tap Dashboard, then tap the name of your thermostat, then the Settings cog icon in the bottom corner. Now you must scroll down to the bottom of a list of options and select “Video Doorbell Linking” and sign in with your Ring/Amazon ID. It was complicated and took a long time to find it. Even the instruction manual and website simply say to “pair your compatible video doorbell,” but with no specific steps.

There are multiple Resideo apps

There’s a lot to like about the HoneyWell Home X8S, but it’s not perfect—and much of the frustration is tied to the Resideo app. In fact, there are multiple Resideo apps at the Apple App Store and Google Play Store—including one I used to set up a thermostat just two years ago—and so it can be confusing to know that only the First Alert app is required. Even the tech support person on the phone acknowledged that many of the calls he gets are because the customer has a different Resideo app installed (including one that controlled a previous model).

Why are there multiple Resideo apps, instead of folding everything into one? At last glance, there is Resideo—Smart Home, Smart Life by Resideo, First Alert by Resideo, Resideo Pro, Total Connect by Resideo, Resideo Academy, Honeywell Home Suite, and others. It unnecessarily makes things more difficult to get going, and as a result, you risk customers packing it all back up and returning it.

To be clear, the app you want to use is First Alert by Resideo.

Warranty

The Honeywell Home X8S includes a 2-year limited warranty.

What owners are saying about the Honeywell Home X8S smart thermostat

A few comments:

• AL on Amazon: AL says, "Bought two, very happy with them and all the features. I like that you can integrate it with Ring door cam, however I am not a fan of Ring due to needless monthly subscriptions. Wish it worked with Eufy door cam instead."
• DW on Lowe’s: "I’ve been using this in our home for about a month now, and overall it’s been a nice upgrade from the previous Wi-Fi thermostat we were using that was about 6 years old. Love the display on this one and the options to select different styles/colors. Especially because it is always on and visible. Navigating and making adjustments on the unit is really easy and intuitive as well. The app is pretty straightforward but I wish it was clearer when the fan was blowing or when the heat/cool was active."
• Stash on The Home Depot: "1 star out of 5. First of all, Honeywell does not even have their own app. You need to use First Alert by Resideo. For the the newest and highest priced thermostat, it has many useless features and very few useful ones. It does not even display when the unit is engaged and running. The temperature sensor is not accurate. I would suggest not purchasing this product."
• Fairshare on Reddit: "Matter and customization is cool. But the doorbell integration has no use unless they support more devices."

Should you buy the Honeywell Home X8S Smart Thermostat?

Yes, is a very competent product that can accurately manage your home’s temperature

Yes. Despite some concerns over the Resideo app—mostly in the initial pairing with the thermostat and linking the video doorbell—the Honeywell Home X8S (available at Amazon) is a very competent product that can accurately manage your home’s temperature.

Along with its core features to assess and make changes to your home’s temp for comfort and/or energy savings, and allowing you to view and control it all from afar, it works well with room sensors (and may be included in the purchase) and offers some added conveniences, like indoor air quality, a “feels like” temp, programmable schedules, reminders and alerts, video doorbell support, and more.

Honeywell Home and/or Resideo needs to support more doorbells than just Ring and the First Alert VX1—but it’s a start.

Hopefully, you’ve got the right wiring to simply replace your existing thermostat with this smarter one, but Resideo does a good job in helping you get going—between the manual, instructional videos, customer care phone access, and a free C-Wire offer. The X8S is a great product, but the app issues around setup are aggravating to say the least.

Starting at $219, the X8S may be more pricey than other Honeywell Home thermostat products—like the sub-$80 Honeywell Home X2S we last reviewed—but it really is packed with useful features and offers a sleeker look between the redesigned hardware and customizable and colorful screen options.