Sensi Lite Smart Thermostat, Data Privacy, Programmable, Wi-Fi, Easy DIY, Works With Alexa, Energy Star Certified, ST25, Most Systems C-Wire Not Required, Except On Heat/Cool Only and Heat Pump System

This was purchased for a church building where areas are unoccupied at various times. This first purchase was a trial. The heating system is hot water with a central boiler serving several zones.We found this thermostat much easier to install and program than a previous brand we had we had tried to use. It connected easily with our existing Wi-Fi. For our system (heat only) it required a “C” wire but fortunately the existing wiring contained a wire we could repurpose. We haven’t used the early start feature yet we’ve just estimated the time to achieve the set temperature and programmed the system to come on soon enough to achieve it. A conversation we had with the the help line informed us that the thermostat will learn the time needed to achieve the correct temperature.The one call to the help line was very useful. The wait to be connected was fairly long, 15 minutes or so, but the gentleman was very knowledgeable and able to answer all the questions we asked. We have also emailed a question and received an answer but the response is slow.We’re pleased with the appearance of the unit it looks very solid and it’s not obtrusive and it is also easy to read. We also like the fact it can be locked to prevent unauthorized adjustment.It has been convenient and easy to install the app on multiple phones and nice to be able to check and adjust programs remotely. It is also nice that it connects to some weather information and displays the outside temperature.It’s great to have the room at a comfortable temperature when you expect it to be.We will also connect the a/c system to it later which now runs on a separate device.We have been pleased with the unit and have ordered two more for other areas.

After Amazon Thermostat, this is totally different experience. Was surprised with quality and connectivity and simplicity of installation. I bouth 2, the full version and lite version, so far so goodWas using for about 3 weeks. Got notifications when door is open, I can set up limit on temperature, which is Incredibly useful for rental.

Works very well, easy control on my phone

I have a home that was built in 2006 and I work in a technical field (engineer) so I am familiar with troubleshooting hardware/software problems. Anyway, my problems with this unit started immediately. During installation, one is supposed to note the letter codes that the existing thermostat is connected to so that the new thermostat can be notified (via wifi and on app on your phone) how to program its terminals to match the original thermostat's functionality. Unfortunately, my existing wire connection was not recognized as being valid by the app (even though my home is relatively new, has a C wire and works properly with the original controller). I didn't let the this deter to me as I was sure I could fine a setup that would work through a little trial/error and voltage measurement. I was able to program my thermostat the first time without any issues; however, the setup I entered didn't work (system produced heat when it should have been cold), so I tried to reprogram the thermostat for a 2nd try. When I searched for my wifi network on the app, I was informed that no networks could be found, which was strange since all my other devices (computers, tablets, TVs, etc) had no issues connecting to my wifi. No problem I thought because I was given the option of entering the name of a network manually, which I did. After entering the name I was asked to enter the network's password twice, which is also strange since double entry is typically required for setting up online accounts, but not for connecting to your own wifi. Anyway, I entered the password twice and things seemed to be okay for a short time, but then the app kept informing me that it was losing its connection to the thermostat. I put the thermostat in "setup" mode by pressing the mode button for 4 seconds, but the thermostat would only stay in setup mode for a few seconds, and whenever it popped out of setup mode, the app would lose its connection again. What was really frustrating is that every time I tried to change the setup, I had to enter the network name and the password twice, which is pretty dumb for a "smart" device! I fought the system for about 2 hours and I was finally able to get another setup programmed, but that one didn't work either. At this point I decided I was done fighting the thing and I returned it. Again, I'm a competent technical person and my heat pump is relatively new and in good working condition. If I can't get it working smoothly, I don't think many others will be able to either. Perhaps I just had a lemon, but my advice is to steer clear of this finicky little monster.

I chose this product because reviews indicated that it would work with a 2-wire heating system, despite the instructions that it required a C-wire. The bad news is that the thermostat will control the heater via the "R" and "W" wire posts using a manual temperature setting, but it will not work with the Sensi app, which is the whole point, right?But there is a solution! I bought "UL Certified Thermostat C Wire 24V Transformer, White Adapter Compatible with Honeywell, Nest, Emerson, Ecobee, Wyze Thermostat and Most Doorbells" and lo and behold it works! Just connect one wire from the transformer (24VAC) to the same post as the "R" wire and the other transformer wire to the "C" post. It does not matter which transformer wire that you connect to the "R" and "C" posts - AC remember?Set up with the Sensi app proceeded pretty well with a bit of try-agains. It seemed that after scanning the supplied QR code with the Sensi app and starting the configuration, the thermostat dropped the wifi connection. The second try worked like a charm, however. Its not due to the wifi signal either - I bought two of these thermostats, one upstairs and one downstairs - same exact result.Now for the Sensi app itself. Setting up a schedule was easy and works well. The geofencing isn't as customizable as I would like, because it only adjusts the temperature setting by 4 degrees. I would like a bigger adjustment when I am away, but this is not possible. I would also like to see more usage statistics in the app. The usage display is rather simple and not very informative. I would also like to control the temperature display on the thermostat, such that it turns off at night, but I don't see how this can be accomplished in settings. Oh well, there is always electrical tape!.