How to Fix a Dehumidifier That Won't Turn On - Dehumidifier Repair

How to Repair a Dehumidifier That Will Not Start

About this repair:

  • Rated as REALLY EASY
  • 34 repair stories

Float Assembly

If your dehumidifier won’t work it may be because the compressor won’t start, because it is not being signaled by the float assembly and switch. This dehumidifier part contacts the float switch when the bucket is full of water to prevent the unit from overflowing. To troubleshoot your dehumidifier, make sure the float assembly is not blocked, so that it can move around freely and come in contact with the float switch when it should. If the part appears to be damaged, you should replace it.


If your dehumidifier won’t work, there may be an issue with the humidistat, also known as the humidity control. This dehumidifier part supplies power to the compressor via electrical contacts when the humidity level in the air warrants it. Sometimes the electrical contacts can become welded shut or corroded, and are unable to signal the compressor to turn on. To perform this dehumidifier repair, turn the dial on the humidistat and listen for the click sound that indicates it is working. You can also test the contacts for continuity using a multi-meter. Replace the humidistat if you find it to be faulty.


If your dehumidifier won’t work, it may be due to a faulty humidity sensor. This dehumidifier part is used on electronic control models, and signals the control board when it senses the relative humidity in the air. The control board signals the compressor to turn on. If the sensor is not working, the compressor won’t cycle on because of an inaccurate reading of the humidity. To troubleshoot this part, inspect the harness connections to the control board to make sure they are in working order. If they appear to be damaged, replace the sensor.

Electronic Control Board or PCB

If your dehumidifier won’t work, and it is an electronic control type, the issue may be the control board or PCB. The control board supplies the compressor and fan motor circuits with power, and will result in the dehumidifier not working if this part is faulty. To troubleshoot this issue, use process of elimination to make sure none of the other dehumidifier parts are causing this issue. If everything is working normally, the control board will likely need to be replaced.

Auto Shut Off or Bucket Level Switch

Your dehumidifier may not be working because there is an issue with the auto shut off switch, also sometimes known as the bucket level switch. This switch is in place to keep the dehumidifier from overflowing when the bucket fills up with water. The float assembly signals the switch when the water level rises to a certain point, which results in the compressor and fan motor circuits shutting off. If your dehumidifier is not working but the bucket full switch is not on, the issue is likely with the shut off switch. Check to make sure the bucket is not full of water, and that the float assembly is able to come in contact with the switch properly. If everything appears normal, test the switch for continuity with a multi-meter.

More Repair Parts

Still not sure which part is broken? We can offer you custom troubleshooting help if you search with your model number.

Enter model or part number

Need help finding your model number?