What happens when my Smart Air Quality Monitor has low signal strength?
FAQ , Air Purification , Troubleshooting Modified: March 19, 2026
The device has a built-in test functionality to confirm placement of the device is in range of the S40 thermostat. If the device is out of range of your S40 thermostat a blue LED will turn on. Regardless of application, the Smart Air Quality Monitor will indicate if adequate signal strength is present. In case of a weak signal, the Lennox Wireless Extender can be used to improve the Smart Air Quality Monitor's signal strength and thus limit the impact of interference by these sources (sold separately).
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