Emerson Sensi Wi-Fi Smart Thermostat for Smart Home, DIY, Works With Alexa, Energy Star Certified, ST55

Works great as they both gave me unable to connect early in but nothing again and I live the easy usage and reporting it gives you too. Easy to mount and connect with a c wire or just a battery too.

This thermostat is the best underrated unit on the market today. You don’t HAVE to have a powered “C” wire (but it is best if you do). It’ll work with 2 AA batteries. Connect to your 2.5G Wi-Fi and get absolute control from your mobile phone. Many configurations possible for central air conditioner/heat or hydronic systems. Has auto heat/cool setting that if set up properly you never need to touch it unless you want to. Or heat only. Or cool only. Does not have auto learning (thankfully) or cameras to muddy up the water. This is the big one #### NO PAID SUBSCRIPTION OF ANY TYPE #### Fairly easy to install and if you need help there is LIVE help if you call I have one in my NJ house and another in my Florida house and I can connect and control from anywhere.

This unit was easy to install and easy to set up. The only issue was that I ended up having to call their tech support and we had to do a "reset" to the unit to get it to find my WiFi so I thought that the installation instructions should have had a contingency for that but it was easily corrected and their tech support is available 24/7 so they even answered on a Saturday evening!! The App GUI is a bit cumbersome and could be a little more user friendly but once you figure it out it works well enough. Overall, I'm happy with the unit and I would definitely recommend it!!

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.

Why did you pick this product vs others?: I came from a Nest Thermostat, two generations, that seemed to never be able to control my central AC system properly. I thought I was making a good decision last year switching to the Ecobee Premium Thermostat after reading all of the mostly positive reviews. It was one of the worst electronic purchases I've made, and I love technology. The one I received never seemed to measure the correct temperature or humidity, and that was with putting plumbers putting in the opening behind the plate. I had to offset both the temp and humidty of it by almost 10 degrees, which is simply unacceptable. That one was replaced, and the second was equally as bad. If you pay $250 for a device that's primary function is to read temperature and humidity accurately, it seems like basic functionality. So, I recently had to start offsetting the temp and humidity on it, and I noticed that it was never reaching the appropriate temperate on the unit all while continually running. As soon as I would turn it off, the temperature on the thermostat would drop two degrees. So, I sought out something different. Enter the Sensi Smart Thermostat. I liked what seemed like a relatively simple device all while having connected integration to Google Home. It was very easy to connect. The WiFi setup was a bit odd as it seemed like it connected, bu the app wasn't really reflecting that. After getting everything fully installed, I was able to get it all connected and registered. I have a hygrometer hanging on the wall beside the thermostat, and I also have an Air Things Air Quality monitor below it that reads both temp and humidity. Guess what - the Sensi has virtually identical readings for temp and humidity to both of them. It just simply works. Configuration and settings were easy. The app is simple and easy to use. I couldn't be happier. Don't waste your money on an Ecobee Premium thermostat, that's for sure. This one right here does the job and does it appropriately and without complication.

Excellent thermostat. Provides the wifi connection that I wanted to monitor and manually adjust temperature. Is programmable, but not required. Which is what I wanted. Instructions are clear and effective for DIY installation.

This is the second Sensi smart thermostat that I have purchased. One for the detached garage and one for the main house. This was purchased from the used section on Amazon at a great savings and functions as the first one I purchased at full price. It is great to know that from anywhere, you can turn on, turn off, or adjust the temperature of the house or set your temperature to switch between heating or cooling automatically. My system does not use the C wire.

Very happy with multiple Sensi wi-fi smart thermostat installations. 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. You need a 24 volt plug in transformer (about $14 on Prime), and some thermostat wiring. The transformer and 2 wire thermostat wire are independent from your furnace and other thermostat wiring. You just connect one end of the two wires to the transformer, and the other end of the two wires to the correct terminals on the thermostat, and plug the transformer into a traditional electrical outlet. Your existing thermostat wiring just gets transferred to the matching terminal markings on the Sensi. Great flexibility with settings and programming with the user friendly app. Controlling and monitoring your temperature and thermostat from anywhere remotely is very handy. Great way to jump into the smart house scene. Edit 1/26/2020 I think I may have discovered the reason so many people are having issues with their Sensi installs and the constant Wi-Fi connection problems. I have four Sensi smart thermostats that I've installed over the course of about a year. The first three installs were very straightforward. Those units have all performed perfectly from the day I installed them. Not a single dropped Internet connection or any other issues. The Sensi mobile app is great, and provides amazing control over programming and controlling the thermostats. I have purchased eight of the Sensi thermostats, but have only installed half of them so far. Most of the units I've purchased have been returns that I've bought for about half price online. Most of them have been registered previously with Sensi. It isn't difficult to have them unregistered through an email request that the app prompts you to do. The two caveats are that you will not have remote access or be able to complete the setup of the thermostat until you are able to register it to your account. The thermostat will still function locally like a traditional thermostat, so that's good. The other problem is that Emerson / Sensi is painfully slow processing requests to unregister thermostats. Count on at least two weeks. You will have to return to the location of the thermostat to finish registering the unit once Emerson gives you the confirmation they unregistered your thermostat. This is the price of buying a returned unit at half price. The fourth Sensi install has been difficult. I revisited the Amazon listing for the Sensi thermostats. I was hoping to find some answers to my install problems from some of the reviews on Amazon. I was quite surprised on the number of newer negative reviews. I originally chose the Sensi because of the positive reviews online and on Amazon. I was having a couple of different issues with the install of my fourth Sensi. Each of my installs were unique as they were for different types of heating and cooling units. Most of my installs were for heat only, including the fourth one. The fourth install was for a Modine warehouse style heater. This required 4 wires. Red heat (Rh), White (W/E), Common (C), and Fan (G). I tested the C (common) with a multi-meter. and I was getting right around 26 volts (correct voltage). Testing is done with the Red lead to Rh and the Black lead to C. The C wire completes the connection and provides constant power to the thermostat to power the Wi-Fi Internet connection. I've seen some comments about not needing a C wire for the Sensi. This may be true, but you will eat through batteries if you rely on them to keep power for the Wi-Fi connection. Technically, you do need a C wire for reliable remote access. My issues included constant dropping of the Wi-Fi and inconsistent operation of the heater and blower / fan. I did check all of the setup parameters for type of heating unit, etc through the app. Everything was set correctly. The Wi-Fi network that this Sensi is connected to is super stable, and has two other Sensi thermostats that maintain reliable connections through Wi-Fi. The issue with the fan I was having is that unless I switched the setting for fan to "on", the heat would not kick on. The correct setting on the thermostat for the fan would be "auto". When set to "on", the fan stays on even when the unit is not heating. If I set my fan setting for "auto", the heater would not kick on. I was fairly confident I had my wiring correct at both the thermostat and at the transformer on the heater side. It's harder to be certain on the transformer / heater side, because the terminal markings are not consistent from manufacturer to manufacturer. I was lucky enough to find a photo online of the terminal markings and what they represented for my exact Modine unit with the same transformer. I was starting to think that this Sensi unit was defective (like many others do based on negative reviews). I did do some wire swapping, but always ended up back where I started regarding the wiring arrangement. Voltages were all reading accurately at the thermostat. I had the face of the unit on and off from the back plate / wall mount many times. On one occasion, while guiding the thermostat back onto the wall mount, I was applying some upward pressure and heard some electrical clicking at the heater as though it was about to kick on. That was my "Aha" moment. The pins that coincide with the thermostat wiring on the main unit / face plate and the related pin openings on the wall mount were not making a good connection. They briefly made a decent connection when I put some increased pressure on the thermostat / face plate. I was able to recreate this heater clicking reaction by pushing on the thermostat. I wasn't certain exactly where the connection was failing (which wire or pin), but I tried a couple of things, and they seemed to have fixed my issues. The first is that I shimmed the back plate away from the wall with a small strip of cardboard behind each end of the back plate and the wall. This would allow the thermostat face plate a little more travel on the wall mount side (deeper seating of the pins). The second thing I did was to go over each thermostat wire where they connect to the back plate / wall mount and reinserted them and made sure that the screws that hold each wire in were very tightly drawn down on each wire. This fixed the fan issue (I was able to set the fan to "auto" and have it turn on and off with the heater). This also fixed the Wi-Fi dropping issue. I'm still waiting for Emerson / Sensi to unregister this particular thermostat, and I will revise my review with an update once I have remote access and can confirm these fixes have remained stable.