Lennox S40 Smart Thermostat
Thermostats
The ultimate controller for more precise comfort
10-Year Limited Warranty
Features
Ratings & Reviews
See what other customers are saying about
Lennox S40 Smart Thermostat
3/5
Great thermostat, but missing key feature
October 07, 2025I’ve had a Lennox system for a while using the S30 thermostat, and loved that it worked with Apple HomeKit. However, the S30 lost communication with devices constantly. It was replaced with the S40, which is much more reliable. Haven’t had a single issue. Sadly though, I miss the HomeKit compatibility. I’m really hoping that Lennox can add it back in an update at some point.
Yes, I recommend this product.
Bossier City, LA
Age: 45 to 54
Gender: Male
Reason for Replacement: Emergency
3/5
4/5
5/5
3/5
Cannot Connect via WIFI
September 23, 2025This thermostat is not as user friendly as my old iComfort S-30 thermostat was. I have yet to be able to connect the S40 to WIFI. This unit DOES NOT broadcast it's WIFI MAC address, so I am unable to put its address in my routers table.
CA
Age: Over 65`
Reason for Replacement: Emergency
3/5
3/5
5/5
Yes, I recommend this product.
Age: Over 65`
Gender: Male
Reason for Replacement: Planned
5/5
5/5
5/5
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