CF appears on the display after a certain number of operating hours; unit otherwise runs normally.

Note: CF is a maintenance reminder, not a failure code.

Steps:

• 1. Remove and clean filter: Slide out the front air filter, wash with warm soapy water, rinse thoroughly, and let it dry completely.
• 2. Clean front grille: Wipe dust from the intake and discharge louvers.
• 3. Reset the reminder: On most Insignia models, press and hold the Filter or Reset button for 3–5 seconds until CF clears. Refer to your user manual for the exact button combination.