Trane Wi-Fi Thermostat ComfortLink II XL950 - CNT06390 / CNT-6390

Bought this from the HVAC dealer who installed our Trane XV20i system.1. I wanted a Nest Learning Thermostat, but after buying one from Amazon, found out that it doesn't work with the 750 speed high end Trane. (Amazon graciously allowed us to return it.)2. Some have reported that the heat produced by the thermostat interferes with its temperature measurement. It therefore needs to be installed where nothing interferes with its heat dispersal. We are having no problems here.3. Others have complained that the XLs don't update because Trane is not issuing updates. Ours is connected to the Internet (which is absolutely optional) and has automatically updated itself at least once, although I'm not sure why it would ever need updating.4. These apparently can be used only with high-end Trane (and the identical American Standard) systems.5. The listing above incorrectly states that the XL950 has a 7 inch screen. It is actually 4 inches. The difference between the XL950 (4 inch screen) and the XL1050 (7 inch screen), beside the screen size, is that the larger model allows a third widget to display; otherwise, the appearance of the two screens is identical, as far as I can tell. We wanted to show the outside temperature, inside humidity, and compressor speed so we 'upgraded' to the XL1050 (which the accompanying photo shows).6. The XLs are not learning thermostats; they can be thoroughly programmed, though. We are retired, so programming is not relevant. If we leave the house, we just change the temperature a couple of degrees. When heading home one of us readjusts the thermostat on our Nexia app (see a screenshot of the app). We got the Nexia app solely to be able to remotely control the thermostat. For that use the app is free. (The great NEST thermostat learns how long it takes for your system to reach your desired temperature and changes the temperature so that when you wake or get home after work your abode will be at that temperature. The Trane cannot do that.)7. I enjoy occasionally changing the color scheme (my wife could care less about this). There are seven color schemes available.8. Our previous (Lennox) thermostat would not backlight the screen unless I pushed some button; the Trane shuts off after a period of time (to avoid burn-in or lessen the heat output?), but by default it shows the set temperature as a screensaver so you don't have to press anything to see it. Alternately, you can plug in an SD card of photos for a slide show screensaver.We are very pleased with our XL and think those that have a good location for heat dispersal and like its abilities over the NEST will be happy with it. Our setup is simple, so we have not faced the challenges of some reviewers who have complicated systems.

The thing I really like is being able to access the things through a smartphone app for Nexia (if all you are doing is controlling a thermostat, there is no monthly fee for this).From a service point of view, the thermostat communicates with the compressor and air handler, and if there is a fault, one can read the details from the thermostat. In theory this makes troubleshooting easier. When we have a tech come out for the seasonal check, the first thing they do is go to the thermostat to look and see if there were any faults.People who have trouble with these thermostats probably just need a firmware update. I have both of mine on version 4.0.3. You can do the upgrade yourself, really. Trane used to have the firmware on their site for you to download, but this is no longer available (some dealers do make it available on their websites however). I assume that they want their HVAC techs doing this kind of service, but most HVAC techs just don't know how to do that - they aren't computer technicians. And really you ought not need to be one - you just need to put the file on an SD card, insert the card, and follow the instructions.

This unit simply can't maintain an accurate temperature. I spent 10K on a new system and this thermostat was not purchased through Amazon. The Trane Dealer came out and "insolated" the wires behind the wall because I was told they were too hot and that is why the readings were off, but the cheap thermostat I had previously worked just fine in the same location. This unit frequently locks up and has no battery back up. When the unit locks up then all HVAC functions don't work. No heat and no A/C. The biggest problem with this unit is the inaccurate temperature readings. You will have it set at 75 degrees and then without any warning it suddenly shows 78 degrees or sometimes even 5 degrees off your set point! I don't know why, but this thermostat reads inaccurately and I am very disappointed considering how expensive the overall Trance HVAC system cost. My installer has been very kind and trying to work through issues, but I am very disappointed in this thermostat. Clearly there is a problem and Trane will not admit it.

Not a smart thermostat unless you want to pay $20 month for Nexia - ridiculous. Everything else in my smart house runs on SmartThings with no monthly fee. Plus, the internet connectivity is awful. Will not hold a connection. Now, after three years of struggling with reconnections, it doesn't connect at all. (I was a network technician, it's not me). OK as a thermostat and works with variable compressor and variable fan in multiple zone setting. Other smart thermostats don't which is the only reason I haven't replaced this bad product. Don't waste your time and money no matter what your mechanical contractor says.

I have this for a multi zone system and as a thermostat it works nicely but it wont stay connected to my home wifi and requires daily reconnect. it also does not cache wifi password so you need to type the password in daily to keep it connected