Diagnosis
Water leaking from the cabinet indicates one of three issues: the internal drain pan is cracked, the condensate pump (if equipped) has failed, or the unit is tilted incorrectly.
How to Fix It
First, check the unit's level. The chassis must be perfectly level front-to-back and side-to-side for water to flow to the drain reservoir. Use a small bubble level on top of the unit. Adjust the height of the casters or add shims under them. Second, ensure the exhaust hose connection to the unit is airtight and sloping slightly downward toward the window. A loose connection can cause condensate to drip inside.
If That Didn't Work
The leak is internal. The most common cause is the drain hose from the evaporator coil becoming disconnected from the drain pan. This requires removing the outer casing to reconnect it. Alternatively, the drain pan itself may have a hairline crack from freezing or impact.
Heads Up
If the unit recently displayed a P1 (Drain Full) error, the leak is likely from an overfull pan. Manually drain it completely. Persistent leaking after leveling suggests a need for disassembly and inspection.