The humidity at home is high, but your dehumidifier has frozen over. What's going on here? How to defrost a dehumidifier? Even worse, this problem seems to keep recurring, especially when you need a dehumidifier the most. Long-term operation of the dehumidifier under icing conditions can damage the machine and may even lead to its destruction. How can we fundamentally solve this problem? We will provide you with answers in the following text.

 

What causes dehumidifiers to freeze?  

Firstly, you need to understand that the working principle of a dehumidifier is to control the temperature to collect moisture and discharge it outdoors. It draws in warm air from indoors and passes it through the condenser coil. When two temperatures are mixed, water vapor in the air condenses and is then discharged through a drainage pipe. Therefore, the dehumidifier requires a significant temperature difference between the indoor air temperature and the condensing coil temperature to function properly.

So, the freezing of the dehumidifier may be due to the room temperature being too low. Water will freeze on the cold condenser coils instead of being discharged smoothly.

Less common reasons include other possible reasons:

Airflow: Due to insufficient airflow, water cannot be discharged from the condenser coil promptly. If this situation occurs, it may be due to the dehumidifier being blocked by foreign objects.

Coil dust accumulation: Over time, dust and debris will accumulate on the coil, which can hinder the discharge of water. In this case, it is necessary to clean the coil.

Filter issue: Overloading the filter can also limit airflow.

 

How to defrost a dehumidifier?

The only way to completely remove frost from the dehumidifier is to allow the ice to melt naturally. Preair LGR dehumidifiers have an auto-defrost function. The dehumidifier automatically melts frost that builds up on its cold coils, especially in cooler or low-humidity conditions (below 60°F/15°C), by temporarily stopping the compressor but keeping the fan running; this prevents ice buildup, maintains efficiency, and allows the unit to resume dehumidifying after clearing the coils, preventing damage and improving performance in colder environments. To ensure the melting of frost, please turn off the dehumidifier and drain the water from the tank. Try to place the dehumidifier in a warmer environment, such as a room with a higher temperature. But do not expose it directly to a heat source, otherwise it may damage the machine.

 

How to prevent dehumidifiers from freezing?  

To prevent the commercial use dehumidifier from freezing again after defrosting, you can take the following steps:

Consider whether the room temperature is too low. If it is too low, please move the dehumidifier to a warmer place at home, lower the air conditioning temperature, or consider purchasing a dehumidifier suitable for use at lower temperatures.

Ensure that there is at least one foot of clearance around the dehumidifier and that the surrounding air circulation is good. This will solve the problem of icing caused by poor air circulation.

Clean the condenser coil. If you are unsure how to operate it, please find a professional to clean it. Do not attempt to clean the coil without turning off the dehumidifier and unplugging the power plug!

If the filter is full, please replace the filter.