Common Dehumidifer Problems and How to Fix Them

Common Dehumidifer Problems and How to Fix Them

Dehumidifiers are essential appliances in our homes, places of work, and other spaces as they reduce and maintain the humidity in the air to comfortable levels. Should your dehumidifier have problems or fail to function as it should, it becomes a priority to have the issues resolved quickly.

These units can have many problems, depending on factors such as your specific model, individual use, and care and maintenance practices. In this guide, we’ll discuss some common dehumidifier issues and ways to resolve them. Read on to learn more.

Why Does My Dehumidifier Freeze Up and How to Prevent It

When the humidifier is operated in low temperatures (typically below approximately 54oF) a layer of frost may accumulate on the coils, which reduces the efficiency and effectiveness of the unit.

The moist air from the room is drawn across the coils by the fan so that the humidity in the air condenses. If the air temperature is too cold the condensation will freeze. Before checking the coils for frost, turn off the unit and unplug it for safety. Evidence of frost indicates that the room is too cool.

To prevent frost build-up there are several solutions you can try:

  1. Turn off the dehumidifier so that the room will warm up.
  2. Turn on a heat source in the room.
  3. Relocate the dehumidifier to a higher position, since heat rises and the air near the floor is coldest.

Some units are designed with an anti-frost sensor which detects formation of ice on the condensing coils. When the above situation occurs, these units automatically activate auto-defrost feature and will turn off the compressor and continue to run the fan in order for warmer room air to cycle and help with the thawing process.

Check this too: Honeywell Dehumidifier How to & Troubleshooting Guide

Where to Place a Dehumidifier in the Basement

You should not place your dehumidifier closer than 6 inches to any wall so that the air intake and exhaust are not blocked. The temperature of the room or area being dehumidified should be at least 65o so that it does not freeze up or burn up the motor, unless the dehumidifier is specifically designed for lower temperatures.

Why is My Dehumidifier Not Collecting Any Water?

If your dehumidifier does not work it may be because the compressor does not start, because it is not being signaled by the float assembly and switch. The 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 freely and come into contact with the float switch when it should.

How to Properly Clean a Dehumidifier

A dehumidifier has several parts that can develop build-up. Regularly cleaning each of these parts can prevent problems that can lower efficiency or even kill the appliance.

Water collection tank

Your dehumidifier’s water collection tank needs to be emptied frequently, but it also needs to be cleaned with soap and warm water or a disinfectant. Mold and mildew can build up fast, and when inside a dehumidifier tank, it gets dispersed into your air, causing illness.

Filter

You are required to regularly inspect your dehumidifier filter for buildup of lint, dust and other materials. A Clogged filter can restrict proper flow and cause undue strain on the unit’s mechanical components, resulting in reduced performance and shorter product lifespan.

Clean the filter periodically. If the unit is used in a dusty environment, you may need to clean the filter on a weekly basis.

To clean the filter on your dehumidifier:

  1. Power the unit off and remove the filter.
  2. Use a vacuum cleaner or gently tap the filter to remove loose dust and dirt and then rinse thoroughly using lukewarm water. You may use mild soap and water solution as necessary, but do not clean the filter in a dishwasher as doing so may damage the filter material.
  3. Allow the filter to dry thoroughly in a cool shaded place.
  4. Reinstall the filter.

Air intake and exhaust grilles

At least once per season, clean the intake and exhaust grilles using a vacuum with brush attachment. Dust and debris build-up can cause blockages that can lead to the deterioration of the unit.

Cleaning the dehumidifier drain hose

To clean the drain hose:

  1. Remove the hose from the unit.
  2. Making sure there are no bends or kinks, flush it with some high-pressure water, like from a tap.
  3. Flush with some white vinegar and soap solution and then rinse with high-pressure water.

Are Dehumidifiers Worth Repairing?

If the issue is minor and just needs a DIY fix to resolve or it can be fixed by a technician, then it may be worth repairing your dehumidifier. Also, the cost varies depending on the dehumidifier model.

How Do You Reset a Dehumidifier?

Many dehumidifiers models from do not have reset buttons, though your particular brand may have one. A lack of a designated “reset” button does not mean the appliance cannot be rebooted; the procedure often involves simply disconnecting the power.

To reset a dehumidifier, follow these instructions:

  • Empty the water bucket used to gather moisture removed from the air down the sink and return it to the appliance.
  • Disconnect the power cord from its electrical outlet and wait five minutes before plugging the dehumidifier back in.
  • The appliance should reset, clearing any settings programmed into the controls. Set the controls and start the dehumidifier as normal.

Dehumidifier Compressor Not Working

Several issues could be preventing the unit’s compressor from working:

Humidistat

If your unit won’t work, there may be an issue with the humidistat, also known as the humidity control. This part supplies power to the compressor via electrical contacts when the humidity level in the air warrants it. Sometimes the electrical contacts can become corroded or welded shut, and are unable to signal the compressor to turn on.

To troubleshoot this problem, follow these instructions:

  • Turn the dial on humidistat and listen for the click sound that indicates that it is working.
  • You can also test the contacts for continuity using a multi-meter.
  • Replace the humidistat if found to be faulty.
  • Faulty Humidity Sensor

The humidity sensor 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 will not cycle on because of an inaccurate reading of the humidity.

To troubleshoot this part, follow these instructions:

  • Inspect the harness connections to the control board to make sure that they are in working order. If they appear to be damaged, replace the sensor.

Electronic Control Board or PCB issues

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, use the process of elimination to be sure none of the other parts of the dehumidifier are causing the issue. If everything checks out and works properly, the control board will likely need to be replaced.

Auto Shut Off or Bucket Level Switch

The auto shut off switch, sometimes known as the bucket level 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, resulting 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 this too: Hevillo Dehumidifier How to & Troubleshooting Guide

To troubleshoot, check to make sure the bucket is not full of water, and the float assembly is able to come in contact with the switch properly. If everything checks out, test the switch for continuity using a multi-meter.

Dehumidifier Not Draining into Bucket

Most dehumidifiers come with a drain hose, but you do not always need the hose if you can empty the bucket by hand or have a drainage system for it. You can drain your humidifier into a bucket.

If your humidifier is not draining into a bucket, make sure that the unit is on a higher level than the bucket. This way, the water from the unit will always be running downhill through gravity.

Dehumidifier Not Draining Through Hose

If your dehumidifier is not draining properly, you should thoroughly inspect the drain setup/ options that have been outlined in the manual.

Dehumidifiers use different drain methods, depending on your model. Your unit may be setup for continuous gravity drain or drainage through am internal pump.

To troubleshoot a dehumidifier that is not draining through the drain hose:

  1. Check gravity drain setup (models that drain collected water via a drain hose by way of gravity)
  2. Check and verify that the drain hose is running in a downhill manner all the way to the drainage port/sink/floor drain. A drain hose that bends or that has been routed to drain water uphill will not work.
  3. Check to make sure that your drain is free from bends and kinks, clogs or other damage that may prevent free flow of water.
  4. If the drain hose has been routed into a drain, like down into a sink or a standpipe, ensure that the hose is not resting in standing water. This will prevent water from draining because of the pressure created by the standing water.
  5. Check to verify that the drain hose adapter has been installed properly. Improper drain hose adapter installation may result in the unit continuing to drain into the bucket, or not draining at all.
  6. Check pump drain setup (models with a built-in pump)
  7. At the drain port on the back of the unit where the pump drain hose is attached there is usually a sensor that detects if the pump drain hose has been properly connected. If the sensor is not properly engaged, the unit will not activate the pump.
  8. The pump will only be activated if the pump drain gas been connected properly. The pump drain hose attachment should “click” into place when properly connected.

Dehumidifier Not Turning On

If the dehumidifier does not turn on, first test that the electrical outlet works by plugging a lamp or small appliance into it. If there is no electricity to the outlet, reset the house circuit. If the electrical outlet works, the problem could be in the dehumidifier’s internal wiring, electronic control board or the user interface control board in the control panel.

There are several repairs you can perform to solve the problem of the dehumidifier not turning on:

Replace the dehumidifier electronic control board

The electronic control board regulates the dehumidifier’s compressor and fan motor. If the electronic control board does not activate the compressor and fan properly, replace the electronic control board.

Here is how to replace the electronic control board on Kenmore and LG dehumidifiers:

  • Disconnect power.
  • Remove the collection bucket by pulling it out of the front of the dehumidifier case.
  • Pull the air filter out of the bottom of the front grille.
  • Remove the front grille.
  • Remove the back panel.
  • Remove the screws that secure the outer case to the dehumidifier and pull the outer case off the dehumidifier.
  • Remove the screw that fastens the fan capacitor to the side of the control box. Move the fan capacitor up and out of the way to access the electronic control board in the control box.
  • Remove the mounting screws that fasten the electronic control board in the control box.
  • Pull the electronic control board out to a position in front of the control box to access the wires attached to the electronic control board. Take a digital picture or label the wires connected to the electronic control board so you can attach them correctly to the new electronic control board.
  • Remove all wires connected to electronic control board and discard the electronic control board.
  • Connect all of the wires to the new electronic control board using your digital photo or labels as a guide. Position the new electronic control board in the control box and secure it with the mounting screws.
  • Reinstall the fan capacitor.
  • Reassemble the dehumidifier.
  • Plug the dehumidifier into the wall outlet to restore power.

Replace the dehumidifier user interface control board

The user interface control board in the control panel houses the selection buttons you push. A wire harness connects the user interface control board to the control board. If the selection buttons do not respond when you push them, replace the user interface control board.

To replace this part, follow this basic procedure below (Kenmore, LG and DeLonghi dehumidifiers)

  • Disconnect power by unplugging the power cord from the wall outlet.
  • Pull the water collection bucket out of the front of the dehumidifier case.
  • Pull the air filter out of the bottom of the front grille.
  • Remove the 2 screws at the bottom of the front grille that secure it to the frame. Lift the front grille off of the front of the grille. The user interface control board wires are still attached.
  • Remove the mounting screws that attach the user interface control board to the control panel. Lift the user interface control board out of the front grille. Unplug the user interface wire harness connection and discard the user interface control board.
  • Plug the wire harness into the new user interface control board. Position the user interface control board in the control panel and secure it with the mounting screws.  
  • Reinstall the front grille.
  • Replace the filter and collection bucket.
  • Plug the dehumidifier back into the wall outlet to restore power.

Replace the dehumidifier evaporator thermistor

The evaporator thermistor is a temperature sensor on the evaporator coils. It communicates the temperature of the evaporator coil to the electronic control board; if the temperature is too low, the electronic control board detects excessive frost and begins the defrost cycle. If the thermistor is not working properly, the electronic control will not defrost the coils. Replace the evaporator thermistor if it does not detect the evaporator temperature.

Replace the dehumidifier humidistat

The humidistat is a sensor on the front of the evaporator coil that monitors the humidity of the room air being pulled in through the evaporator. The humidistat communicates the humidity to the electronic control board through a wire harness connection. If the thermistor is defective, the electronic control will not detect humidity properly and dehumidify the room. Replace the humidistat if it does not sense the humidity.

If the indicator light is on, but the dehumidifier does not run, check the level of water the tank. There is usually a switch that turns the unit off when the tank is full. If the tank is not full, the switch may still have been accidentally activated by the position of the tank. To resolve the issue, try re-adjusting the tank or pushing the switch with your finger.

Dehumidifier Not Reducing Humidity

If your dehumidifier is not reducing humidity and the compressor appears to be functioning it is possible that the humidity setting has not been set low enough for the room in which it is operating. As a result the dehumidifier is not able to run long enough to adequately remove additional moisture from the air. To resolve the problem, try lowering the desired humidity level setting.

If after lowering the humidity setting the problem still persists then you may be having a problem with the humidity sensor or the compressor component.

Dehumidifier Not Shutting Off When Full

There is usually a switch that turns the unit off when the tank is full. If it continues to run without a bucket in place there are several possibilities of where the problem is. The switch could be bad. The wire harness could be shorted. The control board could be bad.

To troubleshoot, check the switch and the wire harness with an ohm meter. If both the switch and the wiring harness are good the control board is bad.

How Often Should You Use a Dehumidifier?

How often you should use a dehumidifier will depend on your home, climate and other factors. To achieve the highest energy efficiency, run a dehumidifier for at least 12 hours a day. This will allow you to remove moisture from the air without racking up the energy bills.

How Long Should You Run a Dehumidifier?

Since size and dampness varies across rooms, there is no set period of time you should run the dehumidifier for, but the following are some general guidelines.

A new house for the most part will display a higher relative humidity reading, so it makes sense to run the humidifier in each room continuously until the relative humidity level is below the 60 percent mark.

Once the relative humidity level is normal, you can then experiment with the different settings during different times of the day until you find out how long you should leave the unit running per day.

As modern dehumidifiers come with an auto-shutoff function, you could practically just leave the appliance running around the clock, and just get back to it when the water reservoir is full. However, this may lead to higher energy costs.

If you are concerned worried about higher energy costs, you may want to go for a dehumidifier that allows you to set the desired humidity level and shuts off automatically when that is reached.

How Long Does It Take a Dehumidifier to Fill Up?

It takes approximately 2-18 hours to fill up a dehumidifier tank depending on the size of the tank as well as the capacity of the unit to pull moisture from the air.

Dehumidifiers have different capacity levels. The capacity refers to the amount of water that the unit can remove from the air.

Check this too: Delonghi Dehumidifier How to & Troubleshooting Guide

When looking at a 50 sq. ft. room at 82°F, we can see that the higher capacity the model is, the more water that is extracted and the quicker the dehumidifier can reach the lower relative humidity level.

Most people choose to let their dehumidifier run 24/7 in order to maintain the relative humidity level that they would like (35-50% is recommended).

Oscar

In his spare time, Oscar loves tinkering with electronics. Solar panels, wiring, old TVs and sometimes DIY powerwalls. When he is not busy trying not to electrocute himself, you can find him in the garden tending to his vegetables and chickens.

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