December 22, 2014

How does a dehumidifier work?

How a dehumidifier works.
How a dehumidifier works.

A dehumidifier is an appliance that removes moisture from the air inside a room or basement, making it more comfortable.

Moist air enters the dehumidifier and crosses refrigerant-cooled coils, causing the moisture in the air to condense on coils within the machine. The moisture then collects in a drip pan or bucket for disposal, while the air passes through a warm condenser or heat recovery coil. The slightly warmed air exiting the dehumidifier is dry and warm.

Three things cause the dehumidifier to turn off:

  • The dehumidifier has a humidity control that you can set to regulate the amount of humidity removed from the air. When the dryness level is achieved, the dehumidifier turns off.

  • The dehumidifier turns off when the moisture collection bucket is full. The bucket must be removed and emptied before the unit will operate again.

  • The dehumidifier uses a de-ice control to turn off the cooling unit if the electronic control detects ice on the coils. After the ice melts, the dehumidifier turns back on.

Most common symptoms to help you fix your dehumidifiers

Choose a symptom to see related dehumidifier repairs.

Main causes: dehumidifier too small for the space, bad humidity sensor, faulty evaporator thermistor, low refrigerant, b…

Main causes: clogged drain hose, drain hose not properly connected…

Main causes: lack of electrical power, wiring failure, electronic control board failure, user interface control failure…

Main causes: room temperature below 65 degrees Fahrenheit, control system failure…

Main causes: weak or dead batteries, out of range, radio frequency interference…

Main causes: dirty air filter, clogged grill, dehumidifier placed too close to the wall, dehumidifier too small for the …

Main causes: collection bucket not installed, collection bucket full of water…

Main causes: loose fan motor mounting screws, loose compressor mounting bracket screws, bad fan, faulty compressor…

Main causes: collection bucket not installed correctly, cracked collection bucket, loose drain hose connection…

Most common repair guides to help fix your dehumidifiers

These step-by-step repair guides will help you safely fix what’s broken on your dehumidifier.

How to replace a dehumidifier sensor assembly

How to replace a dehumidifier sensor assembly

If the humidifier sensor doesn’t properly detect humidity or evaporator temperature, install a new sensor assembly, foll…

Repair difficulty
Time required
 45 minutes or less
How to replace a dehumidifier user interface control board

How to replace a dehumidifier user interface control board

If the dehumidifier doesn’t respond when you try to set it, follow these steps to replace it.…

Repair difficulty
Time required
 30 minutes or less
How to replace a dehumidifier electronic control board

How to replace a dehumidifier electronic control board

If the dehumidifier won’t power up because the control board has failed, use the steps in this repair guide to replace t…

Repair difficulty
Time required
 45 minutes or less

Effective articles & videos to help repair your dehumidifiers

Use the advice and tips in these articles to get the most out of your dehumidifier.

Wiring schematic symbols explained video

Wiring schematic symbols explained video

Learn some of the most common symbols found in a wiring diagram and what they mean.…

How to repair broken or damaged wires video

How to repair broken or damaged wires video

Learn how to repair broken, frayed or damaged wires in your appliances.…

How to use a multimeter to test electrical parts video

How to use a multimeter to test electrical parts video

Learn how to use a multimeter to check for wiring problems in an appliance that's not working…