A slimy substance can coat the bottom and sides of a dehumidifier reservoir. Bacteria and mold spores from the air are the cause of the slime that develops. If left to continue to grow, the slime can begin to have a rancid aroma. The slime cannot be prevented. However, frequent cleaning can remove and prevent the slime from building up and causing an odor.
Unplug the dehumidifier.
Remove the reservoir and discard the water.
Fill the reservoir with hot water and dish soap.
Wash the reservoir with a soft cleaning cloth.
Replace the reservoir and plug the dehumidifier back into the unit.