(S40) Smart T-Stat 4+

The S40 replaced my old white Lennox thermostat that had a dead screen. S30 thermostat was discontinued and unavailable. My only complaints are the expensive $1000 cost, touch screen will not wake unless I wave my hand within an inch of the screen or touch it, and is not Apple Home Kit compatible. S40 works with Google Home ok but I don’t care to use Google Home. The Apple S40 app is designed to work specifically with this thermostat and is required to replace the old Lennox app to work with iPhones. The screen brightness is about right at the very highest setting at all times. The WiFi connection is much more stable than my old thermostat. The outside temperature can be set to display either the outdoor sensor temperature or the local Accuweather temperature.

This thermostat does what it’s supposed to do well, in the sense that it will make the temperature in the house warmer or cooler. However, I have two issues with it. One is just a matter of getting used to in that the temperature of my house feels two degrees cooler than what the thermostat displays. I solved this problem by adjusting the setting up by two degrees.

The lack of a vacation mode is more problematic, and this matters less on departing than on returning home. It can take a solid 24 hours to bring the house to the right temperature after a trip. In winter I set it to 55 degrees and in summer I set it to 85 degrees. I want to program the heating or cooling to begin the day before I get home and to set this up before I leave. I don’t want to have to remember to pull out my phone to adjust this a day before returning home. It should be automated and that’s easy enough to program, but it does not allow this unfortunately. I hope this becomes possible in the future!

Overall the app is mostly functional. The big issue for me is that the smart away function often doesn’t trigger based on geofencing. I went in a trip yesterday over 100 miles away for half the day and the thermostat never recognized that I was away.

As another reviewer mentioned, the proximity option does not work as desired. With the proximity option toggled on, I will need to really wave my hand in front of the device in order for it to recognize and wake up. But then, I’ve noticed that over time the screensaver will never appear like it is always awake.

The sleep options under current temperature does not seem to reflect in the app when the sleep hours are active. I have sleep time starting at 11pm, when 11pm comes there is no sleep icon next to the sensor I have designated as my sleep time sensor. Hours later it seems to finally appear in the app but not at the correct time.

There are some nice to have items as well, such as being able to see which stage cool/heat is running, having humidity displayed along with temperature in the my Home Screen so I don’t need to click on each sensor to view the humidity.

Being able to configure alerts for humidity would be helpful as well, such as a phone notification when a sensor measures over a customized humidity level.