Diagnosis
The float sensor in the internal condensate tank is stuck or the drain port is clogged, falsely triggering the full-tank alert.
How to Fix It
Power off, unplug, and locate the internal drain plug (a small rubber stopper on the back/bottom). Remove it over a shallow pan to drain any residual water. Use a pipe cleaner or straightened paperclip to gently clear the drain port of lint. Reinstall the plug securely.
If That Didn't Work
The float switch itself might be jammed by debris or misaligned. You'll need to partially disassemble the rear housing to access and clean the small plastic float bucket—this requires a Phillips head screwdriver and caution with plastic clips.
Heads Up
In very humid conditions, you may need to use the continuous drain option with a hose. Connect a standard garden hose to the drain port instead of the plug and run it to a floor drain.