How to Bypass the Humidity Sensor on a Dehumidifier

The humidity sensor on a dehumidifier measures the moisture content of air in a room.
If the moisture content exceeds a certain level, the sensor signals to dehumidifer motor to activate and begin drawing water vapor from the room. If the sensor malfunctions the dehumidifier may stop working. Running a bypass on the sensor is a quick way to isolate the source of the problem. However, a bypass is not a permanent solution because the dehumidifer runs continuously in bypass mode.

Step 1

Unplug the dehumidifier power cord.

Step 2

Unscrew and remove the back panel on the dehumidifier using a screwdriver. Follow the path of the two wires connected to the switch motor near the bottom, moving upwards to locate the sensor, which is a 1-inch, black cube.

Step 3

Loosen the two screws holding the sensor wires to the switch, using a screwdriver. Each Y-shaped clip pulls out from under the screw head to release.

Step 4

Strip 1/2 inch of insulation from each end of the short lengths of 18-gauge wire.

Step 5

Wrap one end of the wire around a screw terminal and the other end of the wire around the second screw terminal. Tighten both screws.

Step 6

Replace the back panel with the screws and screwdriver.

Step 7

Plug in the dehumidifier. If it begins operating immediately, the sensor is defective.

Things You Will Need

  • Screwdriver set
  • 6-inch length of 18-gauge electrical wire
  • Wire strippers


  • Unplug the dehumidifier to turn of the unit while it is running in bypass. The unit cannot shut off on its own while the sensor is bypassed.

About the Author

James Clark began his career in 1985. He has written about electronics, appliance repair and outdoor topics for a variety of publications and websites. He has more than four years of experience in appliance and electrical repairs. Clark holds a bachelor's degree in political science.