DIAGNOSIS: The internal condensate drain path is clogged with sludge or the unit is tilted incorrectly.
FIX: Turn off and unplug the unit. Check that it's sitting perfectly level or slightly tilted back toward the exhaust hose (per ). If level is good, the internal drain pan or tube is clogged. You'll need to remove the rear shroud (several screws) to access and clear the algae-like gunk from the drain channel with a pipe cleaner.
IF THAT DIDN'T WORK: A persistent leak after cleaning often points to a cracked internal drain pan, which can happen from ice buildup during a prior fault. This requires a replacement part.
HEADS UP: Never run the unit in Cool mode without the exhaust hose properly vented outside. This instantly overloads the condensate system and causes major leaking.