EmersonSensi Touch Wi-Fi Smart Thermostat with Touchscreen Color Display, Works with Alexa, Energy Star Certified, C-wire Required, ST75W , White

There are many things I like about this device... and I now have 5 in my home.First and foremost, installation. How many times have you taken on a DIY project and found the installation instructions to be wrong or incomprehensible? Emerson has you download the thermostat's app which walks you step-by-step through the installation including ways to deal with various wiring scenarios. And if you are adding a second unit, the app allows you to do so and puts you right back into the installation wizard.The unit itself is easy to install. Most of us are replacing old thermostats and the biggest challenges are getting the wiring correct - and Emerson provides cable labels with each unit - and covering up any holes or painting gaps left by the previous unit. Once you pull off the old unit, it literally takes less than a minute to connect the Emerson unit's back plate and wiring. The back plate also has a small level and light to help!Usability is also very straight forward. Many IoT enabled devices come with far more features and functions than you will ever use. These units easily connect to your home WiFi and allow you to control them from any mobile device using the free app. The app home screen shows the status of all your units and you can update any of them by pressing on it. You can set the temperature using the app, and choose between Cool, Heat and Auto and set temp schedules throughout for every day of the week (or for blocks of days at a time). You can also create alternate schedules for things like vacations or other occasions where you are home or away more than usual.Lastly, you can also easily adjust the temperature (and perform other operations) on the touch-sensitive screen.The units also have low-level backlighting that appears white when idle, soft red when hearing and soft blue when cooling.Great job Emerson!

-------------------------------Update October 2020:--------------------------------Working flawlessly since install. I never notice any issues with it's ability to keep the temperature where I want it.---------------------------------Original Review: Aug 2020:--------------------------------This is a replacement for a Bryant/Carrier T6-NHP 2 wire thermostat used on a carrier Air Handler and a Bryant condenser unit. My problem was that the air conditioner would never stop once it started. I decided that this job is a "Do It Yourself" job due to the pandemic and since I am a retired Electrical Engineer, debugged it on my own.Not knowing much about HVAC, to get started, I had to dig into how it all works. After quite a bit of learning and diagnosing, I finally determined that the old thermostat was malfunctioning. Probably a sticky relay.The first thermostat I tried was the Honeywell RTH7600D which has a dated appearance, and had limited options for different kinds of systems. It would not work with my 2 stage heat pump. Oddly, there was no option to invert the O signal in heat pump mode. Returned.The Sensi cost more but looked more promising. It arrived with virtually no instructions. The idea is you look at web videos and go through the setup screens.Prior to installing, I like to bug out the signals to make sure they work as expected.Two problems here:1) The Sensi needs 24 VAC to work. No sign of a battery. So I ordered a 24VAC power supply.2) The wires are connected to a well designed terminal block on the back plate. No screwdriver needed here, just push to connect, just like a stereo speaker. This block is labeled however, for bench testing, when you snap the thermostat to the back plate to get power, you can access the wires only via probe points. The problem is they are not labeled. I added my own labels here and was able to bug out the unit. Note, there are two methods to bug out the thermostat.1) look for 24VAC on the various pins, while connected to the C wire with the other probe.2) Look for continuity between the Red wire RC or RH and the various output. I found out that the first method is problematic as the unit presents 24VAC to the output when it is active or not. They apparently did not install a pull down resistor on these outputs, and they float high. I consider this a design defect simply due to the confusion it could cause. I suspect it results in a number of returned units, however it is not a functional issue.When I re separated the thermostat from the back plate after debugging, I was surprised to see the LEDs still powered on in the thermostat. Apparently, there is a super-cap or maybe a non-customer battery in there somewhere to keep the unit up through small power glitches.I wired up the unit. and continued the install. Connecting to WIFI was seamless. All it asked for was to identify which network (SSID) to connect to, and the password. Nothing else.The phone app works well also. No connectivity glitches so far.The Sensi does not support the Dehumidify signal on my air handler, but it takes care of dehumidify in a similar way itself. You have good control over that also.The user can also switch on predictive programming, which causes the Sensi to arrive at your desired temperature at the specified time.You can set multiple daily schedules in the app. All pretty straight forward. It appears that you can set as many as 8 set points per day as desired. Unfortunately, the user interface is a bit rough around the edges. Once I created a specific schedule, I could not find a way to delete it. So, just be sure to modify the provided schedule for your first schedule. You can also set the unit to go fan only periodically to avoid stale air in the duct work. The unit knows outside temperature but that is through the web. It does not support the outside temperature sensors provided by my system. I would like to see the unit display the weather on the thermostat, but alas no, but is is on the phone app. It is not clear how much functionality is lost if internet connectivity is lost, but I would recommend a different thermostat if you do not have wireless internet. A nice feature is the web display can show you how many hours the system runs in each mode per day. It does not break down high cool/low cool in 2 stage heat pumps however. I would like to see that feature.There is a modest amount of control over the algorithm, but information provided about exactly what and how the unit does what is does is not to be found. Fortunately, it seems to do its job of regulating temperature in an efficient way pretty well. It is an attractive unit, but be aware that the screen starts to fade out at a 45 degree angle. I will update after I get some more experience, however so far so good.Note: Unit needs to have an internet connection for all but basic functionality.Problem: If unit goes dead, It may not be the unit. Check to make sure you still have 24VAC available. Many HVAC units shut off the 24VAC when the drain overflow switch gets triggered, such as during a drain clog.By the way, Amazon recommended to get a "Emerson F61-2663 Wall Plate for Sensi Wi-Fi Programmable Thermostat", along with this purchase. This is not needed, it is a mistake. Don't order it.

Easy Operations, DEHUMIDIFY options to let it work longer to remove excess %H based on your %H liking, Circulation Fan-only every hour - % time for every hour. BACKlit and plus 4 LEVEL Screen Brightness including complete off. Fast Responsive display, Options to set delay on delay off so as to not wear off compressor with quick on-off switching. Smartphone app is outstanding, works flawlessly, can think of adding any more options or setting in order to operate any Heat/Cool/Pump unitsPEOPLE please test-and-replace your outdoors, compressor-unit STARTER and RUNNING capacitors... (about every 10 years) $10-$20each on amazon. Crazy A/C service personnel asking $500 parts and labor for each! hahaha... Just call them in to test FAN operation, condenser coil clogging, Freon pressures, Capacitors Voltages. If you cant do electric... ask your hoodie handyman, its too simple.Switch off breaker andtakes about 45 min to open cover, move around wire to reach the CAPS, label the wires, remove old, install new and put everything back together. Maybe have to do this twice of get the labels off the old caps for order placement