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Emerson

Sensi Smart Thermostat, 100 Years Of Expertise, Wi-Fi, Data Privacy, Programmable, Easy DIY Install, Works With Alexa, Energy Star Certified, Mobile App, ST55

  • Based on 21,130 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Wednesday, Jul 16
Order within 20 hours and 2 minutes
Available payment plans shown during checkout

Style: DIY


Pattern Name: Thermostat


Features

  • PRIVACY PROTECTION*: Sensi wont sell your personal information to third parties
  • EASY DIY INSTALLATION: Use the built-in level and step-by-step app instructions for a quick installation. Works with HVAC equipment found in most homes. Common wire (c-wire) is not required in most applications
  • 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
  • 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
  • SIMPLE CONFIGURATION: Looks and feels like a thermostat. Has buttons and fits the same space as a traditional thermostat so you dont have to patch and paint your walls

Description

DIY your smart home with the Sensi smart thermostat. Compatible with most residential HVAC systems — no common wire (c-wire) required in most applications. You can trust Sensi as we do not sell your personal information to third parties. And Sensi comes with the dependable performance and reliability you can count on from our 100 years of HVAC experience. With our top-rated mobile app and easy installation process, customers of all comfort levels can make the switch to a Sensi smart thermostat. For more information on Compatibility, Energy Savings, and Privacy Protection, please refer to the “Product Documentation” section below.

Brand: Emerson


Model Name: Wi-Fi Thermostat for Smart Home, DIY Version


Product Dimensions: 1"D x 5.88"W x 3.75"H


Special Feature: Filter Indicator, Clock Display, Fan Control, Auto Changeover, Daylight Savings Time Ready


Brand: Emerson


Model Name: Wi-Fi Thermostat for Smart Home, DIY Version


Product Dimensions: 1"D x 5.88"W x 3.75"H


Special Feature: Filter Indicator, Clock Display, Fan Control, Auto Changeover, Daylight Savings Time Ready


Color: White


Specific Uses For Product: Boiler, Heat Pump, Air Conditioner, Furnace


Connectivity Technology: Wi-Fi


Included Components: Leviton 80409-GY Decora Wall Plate, 2 Gang, Grey


Power Source: Corded Electric


Item Weight: 0.85 Pounds


Voltage: 24 Volts (AC)


Material: Plastic


Shape: Rectangular


Display Type: LED


Screen Size: 5 Inches


Control Type: Button Control


Control Method: Voice


Connectivity Protocol: Wi-Fi


Mounting Type: Wall Mount


Style: DIY


Backlight: Yes


Number of Batteries: 1 AAA batteries required. (included)


UPC: 786710554827


Global Trade Identification Number: 27


Manufacturer: Emerson Thermostats


Item Weight: 13.6 ounces


Department: Unisex-Adult


Country of Origin: USA


Item model number: ST55


Batteries: 1 AAA batteries required. (included)


Is Discontinued By Manufacturer: No


Assembly required: No


Number of pieces: 1


Warranty Description: Warranty.


Batteries required: No


Import: Made in the USA


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Jul 16

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Fairly east to set up, works well with Google Home
Style: DIY Pattern Name: Thermostat
Review Image by James W. James W.
Review Image by James W. James W.
(Long, but I hope worth the read) Overall, I am extremely happy with the Emerson Sensi smart thermostat. For me it was a pretty easy project, but it is important that you know what type of cooling/heating system you have prior to attempting the installation. Although the basic installation is made very simple using the Sensi app, there were some very important things not covered. I suggest you check out how to configure your Sensi on their site (Configuring Thermostat | Sensi US (emerson.com)). I’m a pretty good DIYer, but have very little experience with AC/heating systems. I was 99% sure I had a heat pump setup, but I called a local AC technician I know to confirm and am glad I did. Having installed a few smart thermostats, to include this one, he not only confirmed I had a heat pump, he also informed me I would have to go into the system settings on the thermostat and change the outside setting from ‘AC1’ to ‘HP1’. This was confirmed when I checked out the Sensi website. Armed with this information, installation went without a hitch and I was up and running in no time. Pros: - Easy to install, if you have a little DIY experience, all the information needed concerning your AC/Heating system and gather the additional information before starting. - Very easy to connect to WiFi and integrate with Google Home. Connected to my WiFi with in seconds following the instructions; when I opened my Google Home app, there was an icon to add Sensi, clicked on it and moved the thermostat to the appropriate room. I have not experienced any drop-offs or loss of the WiFi, even when I turned off my WiFi for a few hours, removed the batters or installed old, weak batteries as tests; in every case, the thermostat remained connected or automatically connected right back up in seconds with no need to go through the WiFi setup operations again. - The Sensi app, in addition to walking you through the installation, allows you to set up various cooling/heating programs to run automatically, as well as change other settings. Once added to Google Home, you can switch programs (cool, heat, auto), turn it on/off and set the temp. You can also use voice commands through Google to do this as well. - The ability to adjust the thermostat to compensate for temperature offsets. In my case, where my thermostat is located the temp registers about 3 degrees off from what it is in our master bedroom or living room. I simply adjusted the offset in the Sensi app to compensate for this and now our bedroom and living room remain closer to the set temp then they have in the past. - It can be operated manually by those less tech savvy. The controls on the face plate look and operate like those on our old ‘conventional’ one. I also like that you can lock out the manual operation from the app so that no one else can mess with the settings; like during the holidays when you have family members over who feel they can change the settings without asking .. lol. - Being able to adjust the system cycling rates. There are three settings (short, medium, and long) that can be set independently for heat, heat aux and cooling. I don’t mind having my temps vary a degree before the system cycles back on, so I have all mine set to long; during the summer, I may switch cooling to short to see how much of a difference it makes. Con: I only have one and it is the reason for my 4 rating. The instructions, at least those in the box, should include information on the additional settings that may need to be needed depending on the AC/heating system you have. At a minimum, they should inform you that you may need to make additional setting changes and where to find the instructions online. ... show more
Reviewed in the United States on December 11, 2020 by James W. James W.
    • Step by step app is AWESOME!!!!! Install app BEFORE removing old thermostat.
Style: DIY Pattern Name: Thermostat
We've had this thermostat a month and I really like it so far. It makes me think our old thermostat wasn't actually working for a long time before it started setting itself to 85°. Since it wasn't even programmable, I knew it had to go and if I was going to upgrade I may as well go with something just a bit more...modern than a set-temp-and-it-stays-unless-you-change-it thermostat. I'm going to do pros and cons below. I do want to say, I took my old thermostat off the wall first, wrote down all the wire colors and the letter each was connected to on a piece of paper. The app removes the need for pen and paper. I just used my pen and paper to place the flags mentioned below on the correct wires. Pros: 1. This thing is super easy to install. Open the box and there are instructions for you to download the Sensi app. Once the app is downloaded it has you choose which letter slots you have wires connected to (R, RH, C, E, OB, etc.). The app then tells you how to use the flags they provide to label the wires. For example I had a wire that went into a slot labeled "R", but Sensi only had "RH" and "RC" (I think it was RC), so the app told me which R my wire needed to go in. Not having any electrical wiring experience, the app was SUPER helpful. It even had you take a picture of your wiring to save to your phone, just in case. 2. The piece that attaches to the wall has a built in level. I am super annoyed when things aren't straight on walls, so this right here, was awesome. 3. The app is really easy to set up. I just have a daytime and nighttime cycle, but I could set up all kinds of things super easily. Vacation modes, turning the AC up when I leave the house... It was great. It even walked me through how to sync the app with my Google assistant and the Samsung Smart Things app, which I didn't end up continuing to use. (See cons #1) 4. The report that tells you how long your AC is running is really helpful as well, especially since we had issues last year with it not being able to keep up. We have better insulation and updated windows and it's nice to see they are working, even when it's 99° with a heat index at 112°. (See cons #2) 5. I like that you can do things like temp and humidity offsets, have the AC turn on to help maintain proper humidity levels (we live in Florida, so this is a big thing for me), change the cycle rate (ended up choosing this one over another brand because people had issues with not being able to adjust the cycle rate on that one), and easily turn heat boost on or off. (See cons #3) Cons: 1. It doesn't work with Bixby. This is something I don't really understand, but I'm guessing they assume if you're gonna use Bixby you use Smart Things? But I can just use Google for that instead. 2. The recent usage section only shows how long the AC ran that day, not which times it ran or how long at a time it ran. It would be nice to see how long the AC was running at a time, especially in the afternoon when it gets really hot. I have not yet gotten a monthly report since I got the thermostat mid-June and it's now mid-July. Interested to see what the monthly report looks like at the end of the month. 3. Sometimes I had to change settings a couple times before they "stuck". I found after changing a setting I needed to wait a few seconds before returning to the settings menu and that helped. 4. Shortly after I got the thermostat the AC drain line clogged. This resulted in my app/thermostat constantly saying cooling was on, but the AC wasn't running. My usage for that day was like 21hrs, but I know it wasn't actually on for the majority of that. Not really a huge issue, but you won't have an accurate reading for that day. Summary: Overall, this is a really amazing unit and I have been really glad to have it. It was seriously a breeze to instakl and set up and functions well. I do wish I could connect it to Bixby without using Smart Things and I do wish I had a more detailed daily usage report, but those are very small inconveniences. I normally keep our house at 78° during the day and 77° at night and sometimes that feels cold. I would often feel hot before and wondered if our AC was not working correctly, but it would seem it was actually the thermostat. Very happy with this purchase. ... show more
Reviewed in the United States on July 18, 2020 by Brandi
    • Great thermostat
Style: DIY Pattern Name: Thermostat
I had a hard time looking for a smart thermostat that didn't require a C-Wire and this works great. It was easy to install and connect to the app. I also have it connected to my Alexa and works flawlessly when I tell her what to do and I can use the app anywhere to control it. Definitely worth the buy and may get one for my parents as well. ... show more
Reviewed in the United States on December 17, 2024 by Richie Lopez

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