(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.

Coming from an our old house with an S30, we just replaced a poorly installed contractor grade York system in a one YO new construction home with a Signature series Lennox system coupled with the S40 thermostat. S40 certainly seems more robust and consistent than our old S30 when it comes to communication links and initial setup. I did like the Home Screen UI on the S30 better as it gave more at glance info for the mode the system was operating in or what schedule was being used, if the system was ramping between points, etc. On the S40, I have to dig thru menus to figure out those same settings. The info is there but it’s just not intuitive. My biggest ding on the S40 in comparison to the S30 are the number of steps allowed in schedules. The S40 limits schedules to 4 steps throughout the day. That’s very limiting and impractical given todays reality of daily routines coupled with dealing with power company peak and non-peak rates.

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.