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Sensi Smart Thermostat, 100 Years Of Expertise, Wi-Fi, Data Privacy, Programmable, Easy DIY Install, Works With Alexa, Energy Star Certified, Mobile App, ST55
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Return this item for free
Free returns are available for the shipping address you chose. You can return the item for any reason in new and unused condition: no shipping charges
Learn more about free returns.- Go to your orders and start the return
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Purchase options and add-ons
Brand | Emerson |
Model Name | Wi-Fi Thermostat for Smart Home, DIY Version |
Product Dimensions | 1"D x 5.88"W x 3.75"H |
Controller Type | Vera, Apple HomeKit, Google Assistant, Amazon Alexa, SmartThings |
Special Feature | Filter Indicator, Clock Display, Fan Control, Auto Changeover, Daylight Savings Time Ready |
About this item
- PRIVACY PROTECTION*: Sensi won’t 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 don’t have to patch and paint your walls
Customer ratings by feature
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From the manufacturer
Sensi Smart Thermostat
Designed for energy savings and data privacy - to give you full control of your home HVAC. With over 100 years of HVAC experience, you can feel confident in the product you put on your wall.
-
Data Privacy Protection
Sensi will not sell your personal data to third parties or leverage your thermostat data.
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Control from anywhere
Sensi's top rated app allow on the go control of your homes comfort
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Save about 23% on your HVAC Energy
Sensi helps you save energy with features like flexible scheduling, remote access and usage reports
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Smart Maintenence
Monitor your HVAC system with usage reports, alerts about your equipment, and maintenance reminders.
Videos
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Review of the Emerson Sensi Smart Thermostat
⭐ Mays' Healthy Lifestyle ⭐
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Demonstrating the Sensi App and Alexa Skill
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Product information
Brand | Emerson |
---|---|
Model Name | Wi-Fi Thermostat for Smart Home, DIY Version |
Product Dimensions | 1"D x 5.88"W x 3.75"H |
Controller Type | Vera, Apple HomeKit, Google Assistant, Amazon Alexa, SmartThings |
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 | Thermostat, free mobile app, 2 AA batteries, mounting hardware, wire stickers, installation guide, welcome guide with Sensi code, warranty booklet |
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) |
Item Weight | 13.6 ounces |
Department | Unisex-Adult |
Manufacturer | Emerson Climate Technologies |
ASIN | B01NB1OB0I |
Country of Origin | Mexico |
Item model number | ST55 |
Batteries | 1 AAA batteries required. (included) |
Customer Reviews |
4.5 out of 5 stars |
Best Sellers Rank | #2,276 in Tools & Home Improvement (See Top 100 in Tools & Home Improvement) #8 in Home Programmable Thermostats |
Is Discontinued By Manufacturer | No |
Assembly required | No |
Number of pieces | 1 |
Warranty Description | 3 years. |
Batteries required | Yes |
Import | Made in the USA |
Warranty & Support
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Product 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.
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This Item 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 | Recommendations | dummy | dummy | dummy | dummy | |
Try again! Added to Cart | Try again! Added to Cart | Try again! Added to Cart | Try again! Added to Cart | Try again! Added to Cart | Try again! Added to Cart | |
Price | -27% $94.95$94.95 List: $129.99 | -10% $73.34$73.34 Typical price: $81.55 | $129.99$129.99 | -27% $153.11$153.11 List: $209.99 | -10% $90.00$90.00 List: $99.99 | -12% $79.00$79.00 List: $89.99 |
Delivery | Get it as soon as Thursday, May 16 | Get it as soon as Thursday, May 16 | Get it as soon as Thursday, May 16 | Get it as soon as Thursday, May 16 | — | Get it as soon as Thursday, May 16 |
Customer Ratings | ||||||
Easy to install | 4.7 | 4.0 | 3.8 | 4.4 | 4.1 | 4.3 |
Temperature Control | 4.6 | 4.1 | 3.8 | 4.5 | 3.8 | — |
Tech Support | 4.1 | 3.7 | 3.7 | — | 3.0 | 3.5 |
Alexa integration | 4.4 | — | 4.5 | — | 3.5 | 4.2 |
Smart Features | 4.0 | — | — | 4.0 | 4.0 | — |
Sold By | Amazon.com | Amazon.com | MOESGO Official Store | Amazon.com | NexTechDepot | Amazon.com |
control method | voice | touch | voice | voice | application, touch | application |
connectivity protocol | Wi-Fi | Wi-Fi | Wi-Fi | Wi-Fi | Wi-Fi | Wi-Fi |
power source | Corded Electric | Corded Electric | — | Common wire | Corded Electric | Battery or C-wire |
controller type | Amazon Alexa, Google Assistant, Apple HomeKit, SmartThings, Vera | Amazon Alexa, Google Assistant, IFTTT, SmartThings, Hand Control | Google Home, Amazon Alexa, Google Assistant | Amazon Alexa, Google Assistant, SmartThings, Hand Control | Amazon Alexa, Apple HomeKit, Google Assistant, iOS, Android | Hand Control, Amazon Alexa, Google Assistant, SmartThings |
specification met | — | energy,energy star certified | energy | Energy Star | Energy Star | Energy Star |
material | Plastic | Plastic | — | — | Plastic | — |
Customer reviews
Customer Reviews, including Product Star Ratings help customers to learn more about the product and decide whether it is the right product for them.
To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyzed reviews to verify trustworthiness.
Learn more how customers reviews work on AmazonCustomers say
Customers like the adjustability, interface, and Alexa integration of the hvac control thermostat. They mention that it's a dream to use, and can set schedules for highs and lows. They also appreciate the accuracy, quality, value, and ease of installation. That said, opinions are mixed on connectivity.
AI-generated from the text of customer reviews
Customers find the installation and programming of the thermostat very easy. They say the app interface is simple and walks them through the complete install. They also say the design is easy to work with on mounting and setup, and that the product is convenient to remotely control.
"...Overall a great thermostat. Easy setup. Easy to use. Great features. Very responsive when using your phone. 5 stars plus!!" Read more
"...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...." Read more
"...It’s very simple, but also does the Wi-Fi thing very well. Scheduling, humidity monitoring, statistics, it all works very well...." Read more
"...All around, everything works great. Love this product - makes it very convenient to remotely control your AC.Update: 3/1/2020..." Read more
Customers like the quality of the HVAC control thermostat. They say it works great, is easy to install, and works flawlessly. Some mention that the app seems to work well and be pretty intuitive. Overall, most are satisfied with the product's quality and reliability.
"...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...." Read more
"...It’s very simple, but also does the Wi-Fi thing very well. Scheduling, humidity monitoring, statistics, it all works very well...." Read more
"...All around, everything works great. Love this product - makes it very convenient to remotely control your AC.Update: 3/1/2020..." Read more
"...a few months of use, so as far as I can tell, this unit is completely reliable - it does what I need it to do, no more and no less...." Read more
Customers like the accuracy of the HVAC control thermostat. They say it's easy to adjust temperatures in the app, set up schedules, and use occupancy detection. They also appreciate the ability to change temperature remotely with phone. They like that it allows them to set up various cooling and heating programs to run. They appreciate the good temperature variant that others don't have. They mention that it'll automatically turn on either heating or cooling for these shoulder seasons.
"...Once fully connected you can easily adjust temperatures in the app, set up schedules and use a variety of options e.g. display humidity etc...." Read more
"...5. I like that you can do things like temp and humidity offsets, have the AC turn on to help maintain proper humidity levels..." Read more
"...The accuracy of the t-stat is pretty accurate (within 0.5 degrees of my infrared thermometer)Overall, love the product...." Read more
"...The thermostat outputs the heat in a very smooth way and when the it reaches the set temperature it stops for several minutes and it DEFINITELY..." Read more
Customers like the value of the wifi thermostat. They say it's a great product, reasonably priced, and a worthwhile investment for any modern home.
"...It’s not very expensive, it’s simple and it works great." Read more
"...Easy to program- Check. Cost effective- Check...." Read more
"...and find something that still has the smart capabilities at an affordable price...." Read more
"...Overall I say this is so worth the price. I should have bought this a long time ago...." Read more
Customers like the adjustability of the HVAC control thermostat. They mention that the app is very informative, very configurable, and granular. They are able to set up multiple schedules that are easy to switch between. They also like that they can easily set a schedule and/or temporarily set the temperature. They appreciate the app's user-friendly interface and the flexibility to create multiple programs with as many or as few schedule steps as they wish. Customers also like the ability to learn their preferences and adapt accordingly.
"...fully connected you can easily adjust temperatures in the app, set up schedules and use a variety of options e.g. display humidity etc...." Read more
"...It’s very simple, but also does the Wi-Fi thing very well. Scheduling, humidity monitoring, statistics, it all works very well...." Read more
"...It works exactly as designed.You can make t-stats adjustments either by wifi or LTE on your mobile. No delay in signal...." Read more
"...Well implemented app and easy to follow directions for various types of applications. If you don’t have a “C” wire, it’s relatively easy to add one...." Read more
Customers like the Alexa integration of the HVAC control thermostat. They say it works well with Alexa, and is easy to install and pair with other smart devices. Some mention that the product syncs with Alex flawlessly and is great value.
"...It gives a weekly/monthly usage chart and I can program with my phone. Ive had it 1 month but am still excited with this...." Read more
"...Paired easily with Alexa. Best part: I received a rebate for the entire cost of the thermostat from our gas company!..." Read more
"...Sensi app is wasy to set and change. Alexa compatibilty is better than other smart devices. Amazon's basics model requires c-wire installation...." Read more
"...Works great with Alexa & I must admit that it's pretty nice to tell Alexa to turn up the heat on those cold morning before I even get out of bed...." Read more
Customers like the interface of the HVAC control thermostat. They say the app is amazing, convenient, and informative. They also say the application is clean, easy to navigate, and easy to download. Customers also mention that the product has very good video and help.
"...Not having any electrical wiring experience, the app was SUPER helpful...." Read more
"...The app is excellent, it’s very simple and works great. Installing it also was very easy, even without a c-wire...." Read more
"...you can no longer control the thermostat from the app or it goes offline and the wifi signal disappears or stops displaying on the top left corner..." Read more
"...The android installed app is so good it changes color while viewing if the (in my case) the heat is actually running...." Read more
Customers are mixed about the connectivity of the HVAC control thermostat. Some mention that it's very easy to install and connect to their WiFi, while others say that it would not connect to wireless and that their phones were unable to connect to the app.
"...WiFi connection was made quickly although the thermostat did take 30 or so seconds to be fully responsive to my phone after I thought the connection..." Read more
"...My issues included constant dropping of the Wi-Fi and inconsistent operation of the heater and blower / fan...." Read more
"...No delay in signal. My wifi has never lost signal and has stayed up now for 1 week.The t-stat itself (on wall) has very few settings...." Read more
"...control the thermostat from the app or it goes offline and the wifi signal disappears or stops displaying on the top left corner of the screen...." Read more
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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.
Searching for a thermostat with screen lockout we discovered that none of the good ole Honeywell residential thermostats have this feature. So we moved-on to almost-as-good - almost-as-old Emerson which has this feature on most of their residential products. Out utility company offers a $25 rebate on programmable thermostats and a $100 rebate on WiFi thermostats. With a Prime Day price of $75 this thermostat is basically free. However we were concerned by all the complaints about setup and network problems. So here is what we found.
The good -
1) Excellent manual controls and screen visibility, copied from the refined design of the legacy Emerson line. Most other WiFi thermostats have too much screen clutter in the attempt to eliminate buttons. Old-fashioned buttons really are better for the most common functions even if they don't look stylish.
2) You can control almost anything you want from your smart phone - after you complete setup.
3) You can configure this thermostat to work with almost any kind of HVAC system.
4) You have plenty of flexibility to create multiple programs with as many or as few schedule steps as you wish. For example you can have separate schedules for when you are home, when you are gone temporarily, when you are gone for months at a time. Some reviewers have complained about the difficulty of programming your schedule. Maybe Sensi have improved the app, but I found it reasonably easy to program, given the flexibility.
The bad -
1) The WiFi setup is very finicky. Were I not an engineer with many years of experience with communications equipment I might well have floundered. Common security features in WiFi routers can defeat your efforts. I would note that I recently installed a smart sprinkler controller that is completely programmed from my smart phone and has full remote access capability. WiFi setup was a breeze. I did not have to touch my WiFi router configuration at all. Sensi could do a lot better.
2) The manuals. Yes Sensi, some people do read manuals. Once you get past the simpleton stuff yours are rather poor. "See the App" (which has limited help on some topics) is not a good answer. Things like a list of the menu options and what they do - would be very helpful. The other Emerson thermostats have good manuals - so should yours.
3) Don't bother to call Sensi tech support. You will spend a lot of time on-hold and you might never actually talk to a human. And the support web site was almost as slow. The information is there but you have to be a pro to understand the more detailed stuff. Sensi needs to beef-up their tech support and/or produce a good tutorial on how to connect to a WiFi network. And if they had to write a good tutorial, they might improve their software to make things easier for their customers.
4) I found it necessary to change almost every default setting. Many of the complaints about the performance of this thermostat, arise from not bothering to check every last setting in the app. Better defaults would result in fewer complaints. This problem is confounded by lack of a list of menus and options in the user manuals. If you do not browse carefully through the app, you might miss the setting that you find most annoying.
5) You can control virtually everything else but not the fan schedule. A simple "Fan On or Auto" check box in each schedule step would be great.
The gory details -
If you have read this far, you might want to benefit from some of my experience setting-up this device for my network.
1) First let me explain my network setup. Basically my network has a less-trusted domain and a more-trusted domain. In the less-trusted domain sit my smart TVs, Game controllers, a laser printer that anyone can use, VoIP and media gateways, smart home sprinkler and thermostat controllers, etc. In the more-trusted domain sit my server, laptops, a color laser printer, and a very few other devices.
2) Between my cable modem and my less-trusted domain sits a simple but bullet-proof Ubiquity firewall router/switch. Hanging-off the Ubiquity switch in the less-trusted domain, are a VoIP gateway, a WiFi router/switch, a printer and a guest Ethernet port.
3) The WiFi router/switch serves as a second firewall between the less-trusted and the more-trusted domains. The WiFi hub has both 2.4 GHz and 5 GHz channels, with separate private and guest access, for a total of 4 SSIDs. The router steers the guest SSIDs to the less-trusted domain and the private SSIDs to the more-trusted domain. The private and guest SSIDs have different WiFi access codes (passwords) so both domains are "secure" (in the WiFi sense).
4) By default the guest WiFi clients cannot see each other on the less-trusted domain. This is a common security feature in WiFi routers that support guest access. And it is one of the features that trips-up installation of the Sensi thermostat, but not my smart sprinkler controller.
5) Observing the network interaction between the Sensi app on my smart phone, the Sensi thermostat on the wall, and my WiFi router, at some times the app and the thermostat are operating point-to-point over the WiFi and sometime via the router. So-far so-good. This is expected behavior. However some of the router traffic uses LAN (Layer 2) addresses and some uses IP (Layer 3) addresses. This mixture can mess things up if the network is not configured exactly as the Sensi software developers expected.
6) Sensi should test with other common network configurations. As I mentioned my brand X sprinkler controller does not suffer from these peculiarities. If Sensi invested more money on software engineering and testing with different network configurations they could save a bundle on support costs and customer returns.
My recommendations -
1) Configure your smart phone to use the same WiFi SSID that you want to use for your Sensi thermostat.
2) Be sure this SSID is only available for 2.4 GHz.
3) Go through your router settings to ensure that every WiFi client of this SSID has unrestricted (LAN as well as IP) access to every other client of this SSID.
4) Run the Sensi app through the complete installation and registration process.
5) After everything is working you can restore your normal network configuration in your router and smart phone. Do not change the SSID for the thermostat.
6) If you need to change the SSID for the thermostat later, go back to start. Reset your thermostat and reconfigure your network. Rinse thoroughly and repeat as often as necessary.