Diagnosis
Water leaking from the casing means it's bypassing the internal drain pan. This is usually because the internal drain holes are clogged with algae or sludge, or the unit is tilted forward.
How to Fix It
Step 1: Unplug it and pull it away from the wall. Step 2: Remove the water bucket. Step 3: Tilt the unit BACKWARDS (so the back is lower than the front) over a towel. You might see water drip out from the base—that's the excess you need to drain. Step 4: Using a long, flexible bottle brush or pipe cleaner, gently probe the drain hole inside the unit where the bucket sits. Clear any visible gunk.
If That Didn't Work
The leak might be from a cracked internal drain pan, which is a more serious issue. If clearing the drain hole and ensuring the unit is perfectly level (or even slightly tilted back) doesn't stop the leak, it likely needs a service call.
Heads Up
Using the drain hose constantly without ever removing the bucket can let slime build up in the internal pan. Every few weeks, pull the bucket, wipe out the area, and run a cup of white vinegar through the drain hose opening to keep it clear.