Expert advice on how to repair a dehumidifier that doesn’t work, does a poor job of dehumidifying, or has other problems.
If your doesn’t work right, a simple cleaning of the condenser and moisture-collecting (evaporator) coils may be all that’s necessary to fix it. This article discusses common dehumidifier problems with helpful tips on how to solve them. Please see the list of typical dehumidifier problems top right.
If your dehumidifier shows no signs of life whatsoever:
1Check the power. Be sure it is plugged into a working outlet and is turned on.
2Unplug the dehumidifier unit and check the power cord. If necessary, replace the .
3Remove the cover panel and look for ice. If you see any ice blocking parts, let the ice melt and do not use the unit until the room temperature exceeds 65 degrees Fahrenheit (most dehumidifiers are not designed for use in colder spaces and may freeze up). Many people find that by unplugging the unit and waiting about 30 days into the season the problem is solved.
4Remove and test the overflow cutoff switch. You can do this with a . Clip the leads to the terminals on the switch. Depress the bar or trip lever on the switch. If the meter’s needle does not show continuity and also no continuity as the switch is clicked back and forth, the switch is probably faulty and will need to be replaced.
5Remove the humidistat and check it. You can test a fairly easily using a volt-ohm meter. Also using a volt-ohm meter, you can tell if the overflow switch works or not. Just set the meter to the RX1 scale and attach its leads to the humidistat’s terminals. Rotate the humidistat’s knob as far as it will turn in both directions. If the volt-ohm meter registers zero ohms through only part of the humidistat dial’s range, the humidistat is working. If it registers zero through the entire range, it’s broken and must be replaced.
6If the unit still doesn’t work, decide whether you’re better off replacing the appliance or calling a repair person (this decision will depend upon the value of your dehumidifier)—the dehumidifier compressor motor or the relay and overload switch may be the problem. It’s usually best to replace the
Dehumidifier Does Not Work Well
If your dehumidifier seems incompetent, it may be undersized for the space. Check the unit’s specifications to be sure it can handle the room size. If you don’t want to replace it with a larger one, try closing doors and dehumidifying the space a section at a time. After disconnecting the power cord, you can also:
1Remove the cover and clean the condenser and moisture-collecting (evaporator) coils.
2Lubricate the fan motor bearings with a couple of drops of lightweight household oil (such as ) if the motor has oil ports (some dehumidifiers don’t need to be oiled). While you’re at it, make sure that the condenser isn’t clogged with dust or dirt.
3Finally, make sure your humidistat is functioning properly by testing it with a. Just set the meter to RX1 scale and attach its leads to the humidistat’s terminals. Rotate the humidistat’s knob as far as it will turn in both directions. If the volt-ohm meter registers 0 ohms through only part of the humidistat dial’s range, the humidistat is working. If it registers 0 through the entire range, it’s broken and must be replaced.
4If it still operates poorly, call an appliance repair person for advice or take the unit into an appliance repair shop, or buy a new dehumidifier.
Dehumidifier Overflows or Leaks
Many dehumidifiers have a float switch that prevents the unit from spilling over with the water that has been drawn out of the air. Sometimes this switch goes bad and must be replaced. If your dehumidifier is overflowing, you can test the overflow prevention switch with a volt-ohm meter.
1Unplug the dehumidifier and remove the switch.