Excess humidity levels lead to dampness which promotes mold growth and all the negative issues associated with it. It can also damage furniture and the building itself. This is why having a dehumidifier unit that helps to get rid of excess moisture is important. However, buying a dehumidifier is not always enough. Sometimes there is a fault in the unit. One of such common issues is dehumidifier freezing up. This can be due to a wide range of causes. But why do dehumidifiers freeze up and how can this problem be fixed. Read on to find out.

Read also:

Why Does My Dehumidifier Freeze Up?

Dehumidifier Freezing Up: What Causes It & How To Fix It?

To know why your dehumidifier freezes up, you have to understand how the unit functions in the first place. This will be crucial to diagnosing the correctly and getting it fixed.

The basic mechanism of a dehumidifier consists of a fan, cold evaporator coils, a tank or drain for water, and warm condenser coils. The most unit also features a humidistat designed to control the dehumidifier’s operation based on the humidity level in your room.

To remove excess moisture from the air, the dehumidifier pulls air from the room into its vents. The air is passed through the cold metal coil which causes the moisture in the air to be condensed as water droplets on the coil. These droplets are then removed via a hose or reservoir.  The dehumidifier freezing up means the water droplets remain on the coil where they freeze up instead of going into the dehumidifier tank. Not only does this mean your unit will not function properly, but continual usage of your unit can also damage it permanently.

A freezing dehumidifier unit can be attributed to a wide range of issues. This includes the following:

1. Room Temperature:

The humidity level and temperature of a room are interdependent. Generally, dehumidifiers are only efficient when the room temperature is 65 degrees or over. If the temperature of the air in a room is lower than this, the dehumidifier will ice up causing it to stop working.

The process of air condensation used to remove droplets of water from the air progresses smoothly at high temperatures. But at lower temperatures, the water will freeze instead of just condensing into vapor. This interrupts airflow and stops the dehumidifier from functioning.

2. Air Flow:

Another factor that could cause your dehumidifier to freeze up is an obstructed airflow. The mechanisms of the unit’s operation depend on a free flow of air into and out of the dehumidifier. Hence, if anything happens to prevent the fan from working properly the moisture will freeze up within the dehumidifier.

3. Fault in the unit:

Although dehumidifiers are not very complex, there are made up of different parts all of which must work in tandem for the unit to function properly. Any fault in these components can prevent them from functioning properly. Some of the possible issues include:

  • Humidity Control: The humidistat is the component of your dehumidifier that controls the unit’s operation cycle based on the humidity level in a room. If the temperature in the room is above 65 degrees and it is still freezing up, the problem could be with the humidity control. The humidistat works just like a thermostat. However, it adjusts the dehumidifier settings based on the humidity level rather than temperature. If this part of the dehumidifier is broken or isn’t set to read correctly, the compressor will remain on indefinitely causing the coil to freeze up.
  • Blower Wheel or Fan Blade: These two components of your humidistat are crucial to airflow and help to keep the dehumidifier condenser coils from freezing. They may become blocked by dirt and debris which will impede the airflow and cause water to freeze up on the coil.
  • Fan motor: The fault could also be with the motor of the dehumidifier’s fan. If the fan is not spinning at all or spins too slowly then the motor might be damaged and needs to be repaired or replaced. 

How To Fix Freezing Dehumidifier

How To Fix Freezing Dehumidifier

To prevent some of the issues highlighted above, your dehumidifier has to be monitored and maintained properly at all times. This will also help you discover the issue earlier before it becomes a major problem.

Some of the recommended ways to fix a freezing dehumidifier include:

  • Check the temperature

Before checking the unit itself, the first thing to do should be to check the temperature of the room and ensure it is the optimal operating temperature of a dehumidifier. Use a thermometer to check the air temperature is above 65 degrees. You can also take the unit to another room or position it higher (where the air is warmer) to see if it works properly.

  • Check air flow

The next thing to check is the airflow. Poor airflow can cause the dehumidifier to freeze up. Check to see if the unit is not positioned too close to a wall or blocked by an object. This can stop air from flowing freely into and out of the unit.

  • Check for debris and cleanup

A buildup of dirt and debris is one of the leading causes of obstruction of airflow in a dehumidifier. This is why keeping an eye on the dehumidifier air filter is always recommended. You should also check the fans, coils, and other components for blockages and remove them. Regularly cleaning the unit from time to time also helps to prevent blockages. How often you will need to do this depends on the air quality of your home.

  • Troubleshoot for faults

Some of the faults earlier highlighted such as a broken humidistat, damaged fan motor or blower wheel can lead to poor airflow. If the unit does not work properly after checking room temperature and cleaning it, then the issue could be a fault in any of its components. You can troubleshoot minor issues on your own or simply have a professional check the unit to determine the exact fault with it.


If you discover that your dehumidifier freezes up, it is recommended that you stop using it for a while and give it time to defrost. Continual use when the coils are clearly frozen could result in further damage to the motor and the compressor. There are different possible causes of a dehumidifier freezing up. We recommend that you carefully check all of these possibilities and get them fixed as soon as you notice an issue.