How can I update the software in the Lennox S40 Smart Thermostat?
FAQ , Thermostats , Troubleshooting Modified: March 19, 2026
The thermostat automatically checks for software updates every 24 hours for you as long as you are connected to WiFi. In case you just installed an S40 and do not wish to wait for the automatic update, you can go to Menu > System Settings > Thermostat > About Thermostat > Last Updated and tap the Check for updates now button.
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