Expert Advice on How to Fix a Dehumidifier

If your dehumidifier is not working properly, a simple cleaning of its condenser and evaporator coils can make the difference. Outlined below are the common dehumidifier problems and some helpful tips on how to fix them.

  1. When Dehumidifier Does Not Work Well

If your appliance does not work well, maybe it is not be the right size for that particular room. So, consider checking its specifications to be sure it can handle the room size. If you do not want to replace it, you may consider closing the doors and trying to dehumidify the room a section at a time. Once you disconnect the power cord, consider doing the following:

  • Remove the cover and clean the condenser and evaporator coils.
  • Apply a few drops of lubrication to the fan bearings if at all your humidifier needs to be oiled. Consider using lightweight house oil. Check also whether the condenser is clogged with dirt or dust.
  • Check whether the humidistat is functioning well. You can do this by testing it with a volt-ohm meter.
  • If it still operates poorly, consider calling a professional appliance repairer to come and examine it thoroughly.
  1. When Your Dehumidifier Overflows or Leaks

Most dehumidifiers are equipped with float switches that prevent overflowing of the water that is drawn from the air. Sometimes these switches stop functioning. If your appliance is overflowing, consider testing the overflow prevention switch using a volt-ohm meter. Steps are as follows:

  • Unplug the appliance and remove the float switch.
  • Clip the leads of the volt-ohm meter to the terminals of the float switch.
  • Check the reservoir and empty it, if need be.
  • Check the appliance’s hose and straighten bends or kinks, if any.
  • If the volt-ohm’s needle does not show any continuity when the switch is clicked back and forth, then the switch is probably faulty, and thus you should call a repairer immediately.
  1. When Dehumidifier Freezes Up

If your machine is freezing up, it is good to fix the problem quickly since that may damage the compressor. You can do the following to troubleshoot a dehumidifier that freezes up:

  • Check your room temperature. If the room temperature is lower than 40 degrees F., the appliance will obviously freeze up. A good sign is when the evaporator coil is frosted up completely. If you suspect the room is too cold, try placing your machine on a raised ground like on a table for it to circulate warm air.
  • Keep the unit far from the wall. This is to avoid restricting airflow. Anything that prevents air from flowing freely to the machine encourages freeze up.
  • Ensure the fan is working properly. If you cannot hear the fan blowing air across the coils, then something might be wrong.
  1. When Your Dehumidifier is Noisy

If your appliance makes strange noises, consider doing the following:

  • Disconnect the power and remove the cover. Check for loose screws or vibrating parts. If you see anything loose, fix it.
  • Twist the fan to see if it is loose on the shaft. If it is loose, tighten its mounting fasteners. You can also lubricate the motor’s bearing if that is suggested in the owner’s manual.
  • If the machine still produces unnecessary noises, call a repair person.


The above tips on how to fix a dehumidifier can really help you trouble-shoot your unit. If the problem persists, consider calling a professional or take your appliance to the nearest repair shop.