FAQ How can I address odors and smoke that are not being removed? Clean or replace the filters if they appear to be heavily soiled. See E-15, E-16, E-18 for instructions.Why does the Front Monitor illuminate green even when the air is impure? The air could be impure at the time the unit was plugged in. Try unplugging the unit, waiting one minute, and plugging it in again.Why does the Water Supply Indicator Light not illuminate when the tank is empty? Check the Styrofoam float for impurities and clean the Humidifying Tray. Ensure the unit is located on a level surface.