What mechanisms is the S40 using to clean the air inside my home?
FAQ , Air Purification , Troubleshooting Modified: March 19, 2026
Filtration - at minimum, the S40 Smart Thermostat will run the blower to circulate the air through the filter. We recommend you install a high-efficiency filter such as our Carbon Clean 16®.
Purification - if you have a PureAir S air purification system installed, the S40 Smart Thermostat will run the PureAir S when you need it.
Ventilation - if you have a Healthy Climate HRV or ERV installed, The S40 will run the ventilation system on demand.
For more information or a visual representation of steps please reference our user guide here
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