Diagnosis
The internal drain pan is overflowing because the condensate drain line (if using the hose) is blocked or kinked, or the internal drain hole is clogged.
How to Fix It
Unplug and empty the bucket. Tip the unit back and look at the bottom. Locate the circular rubber drain port. Remove any hose attached. Use a pipe cleaner or small brush to clear the port of algae or slime. Flush with a little vinegar water.
If That Didn't Work
If using the continuous drain hose, ensure it has a steady, downward slope with no loops or kinks. A slight uphill section will cause water to back up inside the unit. Also, check that the hose isn't frozen or blocked by debris.
Heads Up
This leak often happens when switching from bucket to hose drain. You MUST remove the bucket AND ensure the drain hose is properly attached and routed before turning the unit on. Water will flow out of both the port and into the bucket if the bucket is in place without the hose cap installed.