An AC unit leaking water can be caused by several issues:
Clogged Condensate Drain Line: Prevents proper drainage, causing overflow.
Dirty Air Filters: Restricted airflow can cause the evaporator coil to freeze and then melt.
Low Refrigerant Levels: Can lead to the evaporator coil freezing and subsequent water leakage.
Damaged Drain Pan: A rusted or cracked drain pan can cause leaks.
Improper Installation: Can cause drainage issues.
Regular maintenance, including cleaning the drain line and replacing air filters, can help prevent these problems.