This is a great thermostat. I installed it myself including the C wire adapter. I wanted a thermostat that can be set for furnace and AC to automatically change. Make sure you have the unit connected to WiFi so it will connect to you time zone. I connected to my Apple Home app and works fine.
Overall I like it. I have one in my house and bought another one for garage but heat lowest setting is 50 degrees. Prefer to keep garage at 45 or so No can do. House unit works well but noticed today that vacation setting turned off unknown to me and began reheating my home I turned it back on. Not sure about how that happened. Phone did get turned off to fly. Could that be the issue? Doesn’t seem right if so. Like the auto adjust for temp down in evening and back up in morning. Good unit. Easy to connect. Great tech support. If T9 would go down to 40-45 degrees I would have kept the garage unit. Replaced it with a T-4 unit. No more remote access there. No biggie.
I love the new T9 (Honeywell Home now Resideo) smart thermostat. I love the idea of the smart sensors. They keep my home comfortable and I can change which room gets a priority for heating and cooling.
My purpose in buying the T9 thermostat was to better regulate the temperature in our master bedroom during sleeping hours. Using the remote sensor included in the package, that goal has been accomplished. At nighttime I set the system up so that it looks at that sensor only. The system is very flexible in that you can give "priority" to any combination of the devices you connect to the thermostat (up to 20). If you select multiple devices, it will work toward achieving your desired temperature over the average of the selected sensors.
One reason why I purchased the Honeywell T9 as opposed to competitive units (e.g. Nest) is that my understanding is that some of the others will not allow you to set a temperature and hold it. I would rather have personal control over the temperature in my house as opposed to leaving it to a "smart" algorithm.
The installation instructions are very detailed, but I had a couple of problems. First of all, this thermostat requires a "C" wire. If you don't have this wire, you use the included adapter which must be installed at the furnace end. That can be problematic, depending on your particular furnace configuration. I didn't have the a "C" wire connected to the old thermostat, so I thought I needed the adapter and started that install. The instructions give the expectation that there is a nice, neat terminal strip in the furnace to connect to. Instead, my HVAC unit was like a "bowl of spaghetti" wires connected with wire nuts. I finally realized that the HVAC installers DID connect the "C" wire on the furnace end but that it was tucked inside the wall on the thermostat end. With that realization the installation became relatively trivial. The manufacturer covered this in the instructions but it can be easily overlooked. If you have to dig into your furnace the probability of a DIY error increases dramatically. A video would have been helpful.
My other problem had to do with the setup on the thermostat end after completing the physical install. Certain steps can be postponed until later so they say, but if you do, good luck! For instance, my experience was that I couldn't connect my smart phone to the thermostat because I had initially skipped that step. In the end I did a factory reset, didn't skip any steps and the smart phone connection went as planned.
Another issue had to do with the geofence option. Once your phone is connected you are given the option of setting up geofence. I did that but later decided I didn't want that option, but it wouldn't let me remove it! You can temporarily disable it, but you can't totally get rid of it. Note that if you use geofence you cannot setup a daily / weekly schedule. I had to remove the thermostat from the phone app and, once again, do a factory reset to get rid of geofence. After that, no problem.
I am very optimistic that this product will meet my needs very well and would recommend it to others with the cautions mentioned above. It looks good and performs well.