Dehumidifier Coils Icing Up – Here’s How to Fix?

How to fix freezing dehumidifier

Before trying to fix your freezing dehumidifier, it is essential to first understand how it works as well as what makes it freeze in the first place.

A standard dehumidifier has a fan, warm condenser coils, cold evaporator coils, and a reservoir or drains meant to hold water.

It also features a humidistat that works similarly to a thermostat in that it measures the humidity level in the room and controls the humidifier throughout its various cycles.

A dehumidifier works by bringing air into the vents, where it moves through cold metal coils. At this point, the air is condensed and made into drops of water.

The droplets are then pumped through a hose for emptying into a floor drain or stored in the reservoir to empty when full, depending on how you want to handle the water for disposal.

When a dehumidifier freezes up, the water drops aren’t able to get to the reservoir, and instead, a cold breeze is generated.

Once the temperature gets warmer, and the ice starts to melt, the reservoir will overflow, which could cause damage to the humidifier itself. This commonly happens in the summer.

Reasons for a Frozen Dehumidifier

There can be more than one cause for dehumidifier coils to freeze up. The most obvious ones include…

1- Temperature

A common reason for a dehumidifier freezing is the temperature of the room it’s in.

Typically, a humidifier operates at its best in rooms that are around 65 degrees Fahrenheit, but a dehumidifier can freeze up anywhere with a lower temperature.

At higher temperatures, the process of the air getting condensed and turned into droplets happens smoothly.

If the temperature is on the lower side, the water vapor won’t condense and will instead freeze.

This creates problems as the steam freezes around the coil, and the airflow is interrupted, causing the dehumidifier to stop working.

2- Air Flow

Airflow being blocked is another common reason for a frozen dehumidifier.

The flow of air could get obstructed if anything stops the fan from properly functioning or if the condenser is otherwise blocked.

Proper and regular dehumidifier maintenance can reduce the chances of this happening while also making you aware of any such problems sooner.

If you notice ice cropping up on your humidifier, it’s a good idea to stop using it for a bit and give it time to defrost.

Continuing to use it can cause damage to the frozen coils and may make the motor and compressor both over-function and eventually burn out.

It is also recommended that you keep an eye on the filter, as dirt can build up quickly and subsequently block the air.

Cleaning regularly will stop the issue from showing up.

On the other hand, if your dehumidifier comes with a de-icing button, you can also check it. Many basement-style dehumidifiers will defrost any ice that forms on it quickly.

If the switch is faulty, it can cause trouble since there isn’t anything to melt the ice.

How To Repair a Dehumidifier When the Coils Are Icing Up?

Just because the dehumidifier freezes up doesn’t mean it won’t ever work again.

There are a few things you can do to fix it, and because you now have a better understanding of how a dehumidifier works, you can fix it the next time it freezes up while having a good grasp on the actual repairing process.

1- Fan Blade and Blower Wheel

The fan blade and blower wheel are both responsible for keeping the airflow managed and preventing the dehumidifier from freezing up.

It is suggested that you clean the filter regularly by carefully brushing away all of the debris that may have accumulated.

If you still see problems with the airflow after you’ve unblocked the filter, it’s good to take off the cover and look at the coils.

You should also be checking the blower wheel and the blade of the fan. Clean these during your general maintenance routine for best results.

After you have adequately cleaned the fan blade, it’s a good idea to manually move it once to make sure nothing is stopping it from moving once the dehumidifier is started up.

If you notice that the fan blade or blower wheel is damaged, you’ll likely need to repair, if not replace, the part.

2- Humidity System Management

Problems with the humidity management system, commonly referred to as the humidistat, could also cause the coil in the dehumidifier to freeze up.

This technology keeps tabs on the humidity level in the room, and the electric contacts of the humidistat are what is responsible for switching on the compressor in the appliance.

If the humidistat malfunctions, the compressor will stay on since there is nothing to control it, which could result in the coils freezing.

These electric contacts might also freeze shut, which could cause similar issues.

To fix this, unplug the dehumidifier and attempt to turn the humidistat dial. If you hear any clicking, it may indicate that the humidistat is working right.

You can also see if your humidity control is properly functioning using a multimeter.

Remember that the electric contact circuits in the dehumidifier need to be open. If they aren’t, you might have to replace the contacts.

3- Fixing Fan Motor

This motor is what makes the flow of air in the dehumidifier smoother.

To look for problems with the motor, pay extra close attention to the fan while it is running. Use caution when completing this task so as not to damage the motor or injure yourself.

Take a look at the grille and make sure the air is flowing well without any blockage. If you notice blockage, remove the fan cover and clean it.

If the fan isn’t turning or is turning slower than usual, but you hear it humming, you may have to get a replacement.


There are several different reasons that a dehumidifier might freeze up.

Determining the cause will require you to look at it carefully as it is turned on to find out what the problem is, paying particular attention to the fan blade, blower wheel, humidistat, and fan motor.