Keystone air conditioner frequently freezes up; ice forms on the evaporator coil and airflow drops.

Steps:

• Thaw the unit: Turn the AC off and run the fan only, or unplug and let it sit until all ice melts.
• Clean filter and coil: Wash the filter and clean the evaporator fins to maximize airflow.
• Use appropriate fan speed: In very humid conditions, avoid running on the lowest fan speed continuously.
• Check for obstructions: Ensure furniture or curtains are not blocking the intake or discharge.
• If icing persists: Persistent icing with good airflow may indicate low refrigerant or a sensor issue; contact a technician for sealed system diagnosis.