Check the power cord of the dehumidifier. If the power cord is not plugged in, plug it into the nearest appropriate outlet. Make sure the plug is securely seated.
Check the drain bucket. If the drain bucket is full, the dehumidifier will not operate. Remove the drain bucket by pulling it toward you and empty the contents.
Check the humidity control switch. If the humidity control switch is in the "Off" position, turn it to the "On" position to start the dehumidifier.
Check the airflow around the dehumidifier. There should be at least 12 inches between the unit and any obstruction, such as a wall. Move the humidifier if necessary to increase the airflow.
Check the air filter. Remove the air filter cover on the front of the unit, using your fingers. Remove the air filter by gently lifting it out of the compartment. Clean the air filter with your fingers or a damp rag. Reinstall the air filter and replace the cover.