Display shows CF after a certain number of operating hours; unit may still run.

Safety: Turn off and unplug the unit before removing the filter.

Steps:

• Remove filter: Take out the air filter from the front or rear grille.
• Clean filter: Wash with lukewarm water and mild detergent. Rinse thoroughly and allow to dry completely.
• Reinstall and reset: Reinsert the filter. Press and hold the designated button (often "Filter" or a combination like "Timer" + "Down") for several seconds to reset the CF indicator—refer to the user manual for your specific Gree model.