How do I know if the Smart Air Quality Monitor is working?
FAQ , Air Purification , Troubleshooting Modified: March 19, 2026
You can see the levels of pollutants inside your home via the S40 Smart thermostat or your Lennox Home App.
Tap on the "My Home" tab and then tap on your Smart Air Quality Monitor icon. You will see a "Current Air Quality" score along with the score for each of the air quality pollutants being measured.
A gray score means the Smart Air Quality Monitor is not working properly. Call your Lennox dealer to troubleshoot.
You will also be able to view the signal strength of the communication between the S40 Smart Thermostat and the Smart Air Quality Monitor. If signal strength is low, we recommend you call your Lennox dealer to add a Wireless Extender to improve the signal strength (sold separately).
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