Bests & Worsts Reviews from Amazon

I purchased 2 of these 2 years ago in 2016. In the early days I had lots of issues with WiFi connectivity, the fan, and the unit resetting itself. I was in constant contact with tech support as they were rolling out firmware fixes. After a while the units started to work fairly well (except for 1 issue discussed below). I mainly purchased these because I liked the looks and I liked the geofencing feature which allows it to go from "away" to "home" settings based on where your phone is relative to your house. Of the first 2, one had to be returned because it had issues that weren't resolved with firmware updates. One of the two units still seems to lose connectivity for several hours then will just come back online at some point. It continues to operate the HVAC unit during this time, but I can't control it with my phone or the website. If I am at home I can just snap it off the wall (powering it down) and put it back on and it will always connect to the WiFi at that point. The one that I have the issue with is only about 10-15 feet from the router so WiFi signal strength is likely not the problem. Fortunately this doesn't happen that often. But one issue that has always been there is the error in sensing the room temperature. It is always off at least 1.5-2 degrees F. If this was consistent it wouldn't be a problem because you can perform a calibration in the menu. But the problem is that it is typically 2 degrees off, but I have seen it off by as much as 5 or 6 degrees F. I used a Fluke thermocouple reader and a Fluke IR thermometer to test the area around the thermostat. When I snap the thermostat off of the wall and measure the back of it, it really is 2 (or 5 or 6) degrees warmer than the surrounding area. So I suspected that the electronics on the board were heating up the temperature sensing element (a thermistor). I called the company and the tech support guy suggested running it off of batteries instead of the power line coming from the HVAC unit. When I did that it greatly improved the temperature sensing, but now any changes to the system from my phone took 30-60 minutes to update to the thermostat which was unacceptable for me. In battery mode the unit likely spends much more time in an ultra low power mode so there is less heating from the electronics, but also less frequent updates over WiFi. I then took the unit apart and found the thermistor. It is a small surface mount part (Refdes TH3) under the LCD unit on the upper left corner of the board. It was easy to see why this area gets hot as there is little to no air flow since it is sandwiched between the board and the LCD module. More troubling is that on the other side of the board, very close to where the thermistor is, I found the AW6202 Able Trend WiFi module. I looked up the data sheet and under certain situations it has up to 1W of power consumption which is more than enough to cause the board in that area to heat up a few degrees. I assume that when batteries are used to operate this device that the WiFi is turned off most of the time and this is why it doesn't heat up the board as much and results in better temperature measurements. Of course this is only speculation on my part, but clearly moving the thermistor off of the board improved things. Most other thermostats I have seen have placed the thermistors off of the board and off to the side in an attempt to remove it from any heat the board might generate. So I removed the thermistor (it appears to be 0603 size 10k ohm thermistor), connected small 30 gauge wires to it, and moved it a couple of inches off of the board. Suddenly the temperature reading is never off more than 0.5 degrees. This will likely solve my biggest problem with this thermostat, but obviously this isn't a solution for an overwhelming majority of the people that have these so I could never recommend one of these to someone. The only other issue I have with these is that when you are using the wheel to navigate the menu you have to turn it relatively slow or it won't move down the menu. You can't just turn it quickly 5 clicks and have it move down 5 positions on the menu. You have to do it slowly 1 at a time. I think this is due to them not reading the position of the switch often enough so if you move it to quickly it misses each "click".