(S40) Smart T-Stat 4+

Mobile Control & Monitor

Lennox Industries

    • 4.6 • 1.9K Ratings
    • Free



The Lennox Smart Thermostat App allows you to remotely access and control your Lennox S40 Smart Thermostat and advanced accessories from anywhere in the world. Whether it’s adjusting your home’s temperature or schedule, monitoring your indoor air quality or balancing room temperatures, the control is all at your fingertips.
You must own a Lennox Smart Thermostat (S40) to use this app. The Lennox Smart Thermostat must also be connected to your home’s Wi-Fi router before the app can control the settings. For more information go to https://www.lennox.com/products/comfort-controls/thermostats

We truly appreciate your questions and comments. Please keep sending your suggestions to consumeraffairssocial@lennoxind.com or @AskDaveLennox on Twitter.

What’s New

Version 4.26

* Supports iOS 17 Release
* Bug Fixes

Ratings and Reviews

4.6 out of 5
1.9K Ratings

1.9K Ratings

David Farah PHX ,

Huge Upgrade & Great UI

Tremendous upgrade from the S30 iComfort app. The recent bug fixes have been positive. I do like the increased visibility of the system information and the way visuals were incorporated into the app. Frankly, the S40’s capabilities are well translated into this app. Way to go Lennox. Thank you for delivering on what you promised in the ultimate system package.

jbrian00 ,

Needs some fixes

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.

We982075$ ,

No more performance monitoring!

With the older S30 unit I used to be able to monitor my HVAC’s performance on my computer. You could tell how efficient the system was running that way by monitoring on your computer. But now Lennox changed it up and you can no longer monitor performance and see just how your system was working because they knew that that computer feature control gave the consumer power to complain about poor performance, so they eliminated that feature, which is why I am very disappointed with this new system. Lennox needs to get on the ball and get back to what it was which was a good system but now the old system got them into a tight situation because consumers were complaining knowingly that their unit was not performing properly. This was a bad step by Lennox and I wish they would change it. They took a step backwards and I resent that. I don’t think I’ll buy Lennox again.

App Privacy

The developer, Lennox Industries, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Linked to You

The following data may be collected and linked to your identity:

  • Location
  • Contact Info
  • User Content
  • Identifiers
  • Usage Data
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

More By This Developer


You Might Also Like