Emerson Sensi Touch Wi-Fi Smart Thermostat with Touchscreen Color Display, Works with Alexa, Energy Star Certified, C-wire Required, ST75 Black

(10 customer reviews)

Sale Price $149.00

You Save: 12%

PRIVACY PROTECTION*: Sensi won’t sell your personal information to third parties

EASY DIY INSTALLATION: Use the built-in level, illuminated easy-click terminals and step-by-step app instructions for a quick installation; Works with the HVAC equipment found in most homes. Common wire (c-wire) is required

SAVE ABOUT 23% ON HVAC ENERGY*: The ENERGY STAR-certified Sensi smart thermostat can help you save energy with features like flexible scheduling, remote access and usage reports

SLEEK, MODERN DESIGN: The large color display features easy-to-read temperatures and intuitive menus. Available in black, white and silver to complement your home décor

CONTROL FROM ANYWHERE: Remotely control your home comfort from your smartphone or tablet using the Sensi mobile app for Android and iOS devices

SMART MAINTENANCE: Sensi can help monitor the performance and efficiency of your HVAC system by delivering valuable usage reports, alerts about your equipment, and maintenance reminders like filter replacement

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Brand: ‎Emerson


Emerson Sensi Touch Wi-Fi Smart Thermostat with Touchscreen Color Display, Works with Alexa, Energy Star Certified, C-wire Required, ST75 Black 5.625″ x 3.4″ x 1.17″

Smart Thermostat, Wifi Thermostat, Smart Home

Emerson Sensi Touch Wi-Fi Smart Thermostat Touchscreen Color Display

energy saving thermostat

smartphone, smart thermostat, energy savings

easy install, diy, smart thermostat

smart thermostat, data privacy, iphone, android, alexa, smarthings, apple homekit

The Sensi Smart Thermostat puts comfort control at your fingertips whether you are at home or on-the-go. Just a tap of the easy-to-use touchscreen display or free mobile app lets you remotely access, change or program your home temperatures – Anytime. Anywhere. Designed to work with HVAC equipment in most homes* (U.S. & Canada only), Sensi guides you through each step of the DIY installation process with proven, in-app instructions. A common wire (c-wire) is required for all system types.

Refer to our online compatibility resources at to make sure Sensi thermostat will work in your home. Once your Sensi thermostat is up and running, you can let your location automatically adjust your temperature settings with geofencing, or use the intuitive controls to create a custom schedule to fit your lifestyle and save money on HVAC related energy costs.

Sensi touch, compatibility

Additional information



‎Emerson Thermostats

Part Number


Item Weight

‎1 pounds

Product Dimensions

‎3.4 x 5.63 x 1.17 inches

Country of Origin


Item model number



‎2 AA batteries required.

Is Discontinued By Manufacturer



‎5.625" x 3.4" x 1.17"









Power Source


Item Package Quantity


Display Style


Mounting Type

‎Wall Mount

Special Features

‎Wifi thermostat

Included Components

‎Electrical & Heating,Thermostats,household-thermostat-accessories

Batteries Included?


Batteries Required?


Battery Cell Type


Warranty Description

‎3 years.



Date First Available

April 22, 2017

10 reviews for Emerson Sensi Touch Wi-Fi Smart Thermostat with Touchscreen Color Display, Works with Alexa, Energy Star Certified, C-wire Required, ST75 Black

  1. Darrell NashDarrell Nash

    I was looking for a smart thermostat to replace a 16 year old digital one. I was also hoping to find an option that would no longer require batteries. I researched many styles and brands and decided on this one because of a review for it that described how to add the “C” wire to power the unit, the ability to slow the run cycles down and the sleek look. (I think the Nest is way overpriced and looks like it came from the 1970’s) My old unit only used the “Y” “W” “R” & “G” wires which I assumed was all that was available in my home. After reading the review on Amazon I realized that the wire loom between the thermostat and the furnace actually has 7 wires in it. Once I removed the old thermostat and opened up the furnace I found 3 wires in the loom that were unused. Also in the furnace, I found a 2 wire loom that goes to the A/C unit outside. Those 2 wires were attached to the “Y” & the “C” posts in the furnace. (Picture attached) I simply attached one of the unused wires in the 7 wire loom (I chose the orange one) to the “C” post and then attached it to the “C” slot on the installation plate for this thermostat along with the previously used four by following the directions that the phone app walks you through. I then powered the furnace back up and bingo. It works perfectly with no batteries required. I have no idea why this option isn’t more well known or utilized but I couldn’t believe I’ve had the option to set it up this way all along. The app also walks you through how to get linked up to your network which was quite easy. Once linked to my network, I can control it from my phone or the unit itself. My favorite thing about it is that it offers the ability to slow the run cycles down. The old digital unit had such a small upper and lower parameter for the temperature setting that it would cycle on and off every 5-10 minutes. With this one you can put it in a setting that widens the parameters so it cycles much less often and runs longer once it does. I would much rather have the temperature range be slightly wider and not run so often which is easier on the igniter and fan. My only knock is that the display only offers for the temperature to be displayed or nothing when it goes to sleep. I think an option to display the time and outside temperature as well would be cool since the phone app does it already. Last note is the nightlight function is a cool feature to make it look fancy but it would be nice if it had more than one dimmer setting.

  2. David G.David G.

    I have been in the market for a wi-fi thermostat for a LONG time (like 3 years). My main wish list of features was:– Something MODERN looking…like a small cell phone stuck to the wall.– Ability to remotely control my AC (obviously that’s the whole point of a wi-fi thermostat)– Reasonable price– Easy programming– Maybe cool bonus features like playing music, reading email, etc. Based on this list, I considered the Nest but then decided against it. Nests have really nice screens, but I don’t like the round look. That does not say “modern” to me. Also, I work from home so I really didn’t like the idea of having Nest “learn” when I am away (because when I am sitting in my office working, I am not away, but Nest would probably think I was gone).I also looked at a few other brands, but many of these were already looking older/tired. I kept waiting for someone to come out with a new model, but nothing new ever arrived. So, when I saw this Sensi thermostat I thought — hmm, could that be the one? Well, I bought two of these a few days ago from my local big box home store (the blue one, not the orange one). They happened to have a 10% off sale (they were trying to compete with Amazon’s Prime day), so the price was really reasonable. As for the units themselves — they certainly met my criteria of looking like a cell phone stuck on the wall….so CHECK to that box! They also have a cool back light feature which Emerson refers to as a “night light”. If you’ve ever seen the movie Ex Machina, there are scenes where they show some sort of keypad on the wall that’s backlit with very bright blue LED lights. I always wanted something like that, but that’s not really what you’ll get here. First, the night light is very dim, and the light is just plain white. Sort of a missed opportunity there — it seems like for maybe 5 cents more, they could have given you the option of multi-colored backlighting with various brightness levels. Ho-hum, maybe the next version will include that. Anyway, overall I am VERY impressed with these things. The backlight is still pretty cool, even though it’s not terribly bright. The screen is also VERY nice….not quite as nice as a modern cell phone, but much sharper and better than other brands I’ve looked at. One minor complaint — you can’t actually leave the screen on full time. Instead, the screen will “sleep” after about 10-15 seconds. At that point, you have the option of allowing it to go full dark, or you can have the screen remain on with only the temp showing, but with a very dim screen. Some of the photos attached to my review show this — if you see just the number 78 on the screen with nothing else, that’s the “sleep mode”. It’s very dim, but the screen instantly returns to full brightness if you tap it anywhere, so no huge issue. I feel like this is not a big deal….do you really need your screen to remain on when you’re not using it? I don’t, but on the other hand the screen is so nice, it would be better to give consumers the option of leaving it on. My guess is they will push out a firmware update that add that option, and even if they don’t, it’s not a deal-breaker. If I have any other complaint, it’s just that the default temperature setting did not seem to match my room temp (I have other thermometers in the same room reading 84 degrees when my Sensi is displaying 78). Yes, there is a setting in the app to adjust this, but you can only go +/- 5 degrees. In my case, I adjusted the setting by a full 5 degrees, and I am not sure that’s enough. This isn’t a life or death problem….you can always just set the cooling temp a few degrees lower to make the room comfortable (i.e., I used to keep my AC set to 78, but now I need to set it to 74 because the thermostat thinks the room is colder than it actually is).Having said all this, I still think these units deserve a strong 4.5 star review….which I’ll round up to 5. Yes, they have a few minor issues, but overall they are a solid value if you’re in the market for a new thermostat (and no, they don’t play music, but really, that wasn’t a serious requirement).P.S. These also were VERY easy to integrate with my Amazon Echo, so now I can change the temp just by yelling out: “Alexa, set downstairs to 76 degrees.” This works instantly and seamlessly. Very impressive .P.P.S. I hate the lack of user-submitted photos, so I have attached a bunch…enjoy!

  3. rpiotro

    Now that I have had it for a year I feel qualified to comment. I replaced a Honeywell that had a problem with the touch screen. You had to push real hard to make it work. Support was useless. Never returned my calls or emails. Now for the Sensei. It works great. It keeps the temperature very even. No big swings. I have a calibrated thermometer and hygrometer. The ‘stat temperature was spot on and the humidity was off by about only 4%.As far as configuration goes there are multiple settings. You can adjust the offset for both temperature and humidity to account for a slight inaccuracy. I corrected the temp by 1° and humidity by 4%. It has a circulate mode for the fan that even allows you to set the percentage of the run time. Fantastic! You can set a dehumidification mode also where it will run the AC as needed to reduce the set level. It will only run up to a few degrees cooler so it does not turn into an icebox. You can also set heat and cool cycle rates if you are willing to sacrifice a little bit of efficiency in exchange for holding the temperature in a tighter range. Minimum and maximum set points are available and you can also lock the thermostat so it is only available from the app. There is also a geofencing option. I’ve never used it so can’t comment. The only weakness is this. It has an “early start” option that will anticipate so that the set temperature is achieved at the set time rather than the system starting at the set time. I have a two stage furnace. The thermostat is supposed to command setting the furnace to high mode if the temperature is raised more than 2°F. It will indeed do this if I manually change the temp. If the temp is raised from the schedule it will not go into high until the furnace has run for a while. A little disappointing but not a deal breaker. I called support about this and they were helpful but all they could do was pass this along to the developers. I suspect they feel it is an efficiency issue. The Honeywell did work correctly in this regard. This is my fifth smart thermostat starting with a Honeywell Chronotherm. Then a WiFi Honeywell that died after five years. Then another Honeywell that I hated. A Bosch that I returned after two weeks and now this Sensei. This is hands down the best of the bunch.

  4. Linda Torres

    I had an old thermostat made by Carrier I was tired of. I called and asked them for help. They were no help at all. So….I got onto Amazon and found this little jewel. It was a breeze to install. The wires were exact. The position of the screws were exactly the same. E-Z Peazy. Connecting it to my home network was only a tiny bit tricky because it wasn’t working using my iphone. But, as soon as I switched to using my ipad for connecting to my network….it connected right away. E-Z Peazy. And after initial connection, it works well on my iphone. I love it that the app is right on my phone and I can be anywhere in the world and can adjust the temperature in my house. Although, most of the time, I’m just in bed, waking up, deciding, luxuriously, what temperature I would like when I rise. Life is good.

  5. Chelpiper

    I am not an electrician so please do not see this review as any guidance to do the installation yourself, please hire an electrician. I did have to use the common (blue wire in my case) but that was very easy to do since the common wire was one of the wires that was available to use once I found it tucked inside the wall. Installation was very easy and the instructions were very good. Once the thermostat powered on, I used the app to walk through joining my network which was very easy. It did fail to join the first time but the 2nd time worked. I then sat down and played with the app where I set the schedule. The presets were actually very close to what I had before so there were minimal changes. Keep in mind, schedules are designed to save you money by not hearing or cooling your home when you are away. So if you take a day off in the middle of the week you will need to manually adjust the temperature which is easy from either the app or the really nice touch panel. There are a lot of features with this thermostat. One that I really like is that I have the fan circulating fan kick on once per hour for 15 minutes to recycle the air. I have noticed a reduction in dust in our home since I’ve enabled this feature. Something to note is that there are a handful of additional features on the physical panel that are not available on the app. Maybe in the future they can add these extra controls to the app. This device has a great panel, very clear to read and operate. It has different dimmable display lights, as well as a “night light” which is nice. The display turns orange when heat is running and blue when cooling. I am planning on buying a 2nd one for our upstairs furnace/air conditioner and using their special multiple thermostat app (10 bucks per year I think is the charge) to manage both thermostats in the same app. I hope this is helpful for someone. I did a lot of research and struggled with which one to choose but I am very happy with my choice and has just the right amount of features. I look forward to trying their Geofencing feature. Thanks

  6. ToolTimeTommy

    I just replaced a 37 year old furnace and 20 year old AC unit… so I figured it was time to update the thermostat as well. I looked at the Nest system and a few others and decided I didn’t need that much home integration. I have a weather station and don’t need a thermostat that tells me the outside weather, or many of the other features others offer. What I did want was a sleek looking digital WiFi controlled thermostat, that I don’t have to track when I last changed the batteries in. The Sensi provides everything I needed. Control over the basic HVAC functions, and a simple scheduling app, along with a simple and basic usage report. The installation took less than 20 minutes, the phone app had detailed instructions including wiring guides. Once installed and connected to my home network it instantly updated the firmware and set the date and time. I like the color change indicating the system is running, blue for cooling red for heating and grey for idle. I like the option to set the system fan to circulate air when the system is idle. I am quite happy with my purchase.

  7. Rick

    Update #2 (2 Dec): Just a quick update to report that the thermostat has been working great now for over three weeks… no glitches, no wifi disconnects, and no reason to believe there will be any issues. The connection to Alexa is also great and very responsive. Very happy with this choice for a new thermostat! Update (10 Nov): I’ve updated my rating to 5 stars now. The Support team contacted me by email and provided a detailed rundown on configuration settings available under advanced settings. It turns out that the Sensi had auto-configured to a different type of furnace than I have, so once I made the appropriate changes I was able to reconnect the Green (fan) wire and the unit works properly. I’m not sure why this information isn’t provided in the setup documentation, but I appreciated the Support team providing a courteous, prompt and detailed response. I also loaded the Alexa skill for Sensi, which set up quickly and it works well. I can now inquire about temperature or change the setting by voice. And of course when away from home, it’s nice to have a single app (the Alexa app) where I can communicate with furnaces, light switches and electrical outlets if I want to. The bottom line after having the unit in place for several days: I like it and am rating it 5 stars. Yes, it was a little painful getting here, but it’s doing what it’s supposed to, it’s very easily programmed with any schedule you like, the wifi continues to function normally, I like being able to check my phone from anywhere and see what the furnace is doing, and I really like the way it looks on the wall, including the color change when it turns on the furnace and the dimming feature that provides a dim display of temperature that isn’t overly bright or annoying at night (of course, you can shut this off). I like it enough to overlook the start-up issues. Providing it continues to work properly in the coming weeks and months, it’s exactly what I was looking for. Original review (8 Nov): Although there are mixed reviews of this thermostat, many of them appeared to be software related, and software can be updated if the company stays on top of issues, so I thought I’d give it a try anyway. It’s definitely a nice, sleek looking unit, and programming/using it is straightforward and very flexible as you can set up virtually unlimited schedules. Hooking it up was pretty easy, as there is normally no real rocket science to thermostats and furnace control. My upstairs furnace is about 18 years old, and control requires minimal wiring. So while the original thermostat had 4 wires connected (Red for 24 VAC power, White for heat call, Yellow for cooling call, and Green for fan control), I had no common (C) connection available at the wall. Fortunately, the cable had six wires in it, so a 10 minute visit to the attic (where the furnace is located) and I had one of the spares connected to the furnace C terminal. Fired the furnace back up and the Sensi came to life… and this is where some minor troubles began. Setup to wifi requires doing a little configuring using the Sensi app. I installed the app on my Samsung (Android) phone, which completed quickly. Unfortunately, when the Sensi wifi transmitter was supposed to be transmitting, the app was unable to find it. Checking for all wifi signals on my phone, there was no signal from anything other than my router and a weak router signal from a neighbor. I tried switching the Sensi wifi on/off a few times with no results. Then I found a system reset option, so I tried that and the display simply hung… no reset, and no ability to do anything. I figured this might be a good time to call the Support number, which I did. They responded within a couple of minutes (which is great), and the solution was a power cycle, accomplished by simply removing the Sensi from its base on the wall and putting it back after 5-10 seconds. This time, the wifi came up as it should, so I hung up with Support and I was able to configure the thermostat. I noticed the room temperature indicated 77 deg, which was about 9 degrees higher than it actually was, based upon two other digital thermometers that both read exactly the same (68 deg). Then, about 5 minutes later, after tinkering with system options in the app and finding a temperature offset adjustment that provides only up to plus or minus 5 deg (well short of 9 deg), suddenly the Sensi went offline and the initial wifi setup screen returned on the unit. At this point, I could have just gone thru the wifi setup again, but with the significant temp inaccuracy, I thought I’d call the Support guys again and discuss what was happening. Again, they picked up within just a few minutes. The solution here was trying a system factory reset, and this time the splash screen came up after half a second rather than hang like the first time that I tried it earlier. Apparently, the factory reset also initiates a calibration, which for some reason can take a full day to complete… but it doesn’t impact being able to use the thermostat. So, following the reset, I hung up and completed the setup again. Things were back to normal, and within a couple of hours the indicated room temperature slowly moved downward to within 2 deg of those other thermometers. By the next morning, it was still 2 deg off, so I selected the -2 deg offset and all was well. So clearly, the calibration function works fairly well. After operating for a while, I found that the cycle rate was much too fast as the furnace would start back up shortly after shutting down, so I adjusted that to the “slow” setting. After letting it run overnight, I discovered in the morning that I no longer had heat! After a little checking, it turns out the flame sensor in the furnace was no longer detecting the flame, which after a few seconds shuts the flame off. After three such cycles, it locks the furnace. This wasn’t initially apparent because the Sensi wants to start the blower fan when it calls for heat, so it sounds like the furnace is running… except it’s blowing cool air. Furnace electronics are designed to allow the furnace to start up and develop a little heat prior to starting the fan… this is unnecessarily overridden by the Sensi. My belief is that this air flow starting before the furnace ignited must have had some effect on an old and somewhat dirty flame sensor. Cleaning the sensor fixed the start-up problem, but it still makes no sense to blow cold air out the ducts on start-up. So for now, I simply disconnected the Green fan wire attachment in the Sensi base, and everything is working normal. I sent a summary of this concern to Sensi in writing, questioning whether there’s an app setting I missed, or this unit (when set for gas heat) is defective, or perhaps this feature is a design flaw. I’m awaiting a response. One other note: there’s apparently at least one little bug in the app… occasionally when you’re connected to a specific thermostat and you use the back arrow button to go to the previous screen that lists all thermostats (of course I only have the one), the app will display it’s “working” indicator (an animated blue target looking thing) continuously and not take you back to that screen. Killing the app and starting it up again returns things to normal. It’s minor, but it has done it a few times and it would be more pleasant if it always worked. So after a rough start, things seem to be working, albeit with my little Green wire modification. I’ll update this review as I learn more or if there’s a failure anytime soon.

  8. Molly Jo

    It’s basic as far as a Wi-Fi tstat goes. However, if that’s what’s your looking for (which I was) then you can’t go wrong with the Sensi Touch. It VERY EASY to install. Emerson does a fantastic job in provided very straightforward directions and the Sensi App takes you step by step through the very short process. I think it took me 10 minutes to set it up and connect to my network. The unit itself is very stylish and I really like the touch screen. The app is very intuitive and is really where you should do all your settings and adjustments. Customer support is outstanding. There is currently a glitch in the software that gives you an error with the current time shown on the unit. I called Emerson and within a couple of minutes I had that fixed. Everything else was perfect after initial setup. It’s not the cheapest unit out there, but you get what you pay for. This one is truly a keeper!

  9. Stephen Furr

    I have had the older Sensi Thermostat for a couple years now. I love that thermostat and I will still use it. I will be setting that up in my detached garage. Issues I ran into that one with, did come to haunt me with this upgrade. I used to wonder why my old Sensi Thermostat, which was connected to the common wire (black), required batteries to operate correctly. I help a friend out doing HVAC, but I do most of the grunt work. So, after installing this new, Sensi Touch Thermostat, I found it to have no power. This thermostat does not take batteries. I had hooked it up the same as my old Sensi, and as I had finally figured out, my common wire (black) was not actually live. To make sure, our thermostats come with a jumper wire. I used this jumper wire to go from the red (power) to the yellow (air) in the thermostat. I then waited a minute or so, and my unit kicked on. That told me the unit was good and that I had no power to the thermostat. This is the bypass. I have yet to go under the house, but my friend who is in the business, states this is common. I had to take the panel off my outside unit to get to my thermostat wires. I decided, since it was around 11PM at night that I didn’t want to go under my house, so I tried using the other, available common wire (blue). I replaced the black thermostat wire, which was connected to the blue wire from the unit, with the darker blue thermostat wire. I was lucky. That wire was hooked up correctly under my house. So, the only reason I share this information, is because I could not find it in Google, on the White-Rodgers/Emerson Sensi Q&A, nor Youtube. I don’t want people to give this a bad rating for an experience like mine. It’s a great product. I will eventually have both thermostats displaying actively on my app. I have also seen some reviews stating issues setting up because the person does not have a cell phone, wifi, or ability for apps. This is a Wi-Fi thermostat. I can’t go purchase products for a smart home, without smart home capabilities, and expect things to work or install correctly. This thermostat is for those with today’s technology.

  10. Shooter M.Shooter M.

    I waited a couple of weeks to install because I was slightly nervous about how long it would take me to figure out the wiring of one of these as I’ve never done it before. I finally got a few free hours in the afternoon, and as you can see in the picture of the old thermostat, it was 76 degrees in my house on October 9th in Wisconsin! The thermostat came with my house, and I could never figure out how to set it correctly. I thought I had set it to hold at 72… but that’s the problem with it/me I guess. I wanted something simpler (and cooler) so I got this one from Amazon. I was slightly worried when I opened the box and there weren’t really any directions to install. Just a small “getting started” pamphlet that directed you to download the app. Well, OK. After downloading the app, I was amazed! The app takes you step by step through the installation. I was worried about the wiring. Well, when you get to that part, they have a series of short videos to watch. Basically, your new Thermostat needs a “C Wire” or “Common” wire which most newer HVAC systems apparently have or have the capability of having. My system is only 10 years old, so I assumed it had one. Well, it didn’t. So, the videos start with one explaining the C Wire. Then a short one showing you how to tell if you have one. Then if you don’t, there’s 3 ways around it depending on your setup. You watch all 3 of those short videos (around 2 min each) and figure out the easiest way to set it up based on your current system. I needed to move a wire on my heater and use a jumper wire. They even included a jumper wire in the box! They included little wire label stickers so that you can remember which wire is supposed to go into which slot on the new thermostat even. This installation kit is really well done and specifically designed for DIY’ers like me. Trust me, unless you have a super old and out of date HVAC system, you’ll love this thermostat. As you can see in the pictures, by the time I got it set up it was 80 degrees in my house. I set it to 72 by simply tapping the down arrows… and the A/C kicked on immediately. Now it’s a comfortable 72 and the cool night light behind it on the wall looks fantastic. It DID take a little monkeying around with the WIFI to get the app connected, but a quick google search took me to the Emerson help page and their solution worked right away. I could not establish a secure connection through the wifi with my phone. So, I had to open the WIFI settings on my phone after the app got the error and connect to the Sensi WIFI network it had created. Once that happened, then you set up the Sensi to connect to your home WIFI and that’s it! I’ve only had it set up for a day, but unless there’s an update on here, you can assume it’s still working and I’m still loving it.

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