Why Dehumidifier Freezing Up?

When your dehumidifier freezes up, it is not able to effectively remove the moisture from the air. Why does that happen and how can you avoid such a situation?

The dehumidifier can freeze up in case the temperature in the room is too low, there is a lack of airflow, and the defrost mode had failed. Such mechanical and electrical failures as faulty wiring, a refrigerant leak, and a burnt compressor can also be to blame.

Why Dehumidifier Freezing Up?

The room is too cold

Every unit has a recommended temperature range in which it can operate. As soon as the temperature falls below that range, the unit will stop working and might freeze up.

For a lot of dehumidifiers, the bottom temperature lies at around 65 F. Lower temperatures can cause ice to form on the condenser coils.

Insufficient airflow

If there is not enough air moving through the device, the coil might freeze up as it can’t efficiently exchange heat with the air.

This might happen, if something is blocking the dehumidifier, if the air filter is clogged, or if there is an issue with the blower wheel and/or fan motor.

By the way, the air won’t be able to circulate through the unit properly, if the coils are covered in dust and dirt

Failure of the defrost mode

Typically, dehumidifiers have their own defrost mode that should melt the ice on the coils if there ever is such an issue. However, there are quite a few things that can cause the malfunction of this feature.

A faulty humidity sensor, for example, that is not able to read the correct humidity level won’t send the right signal to the part of the system responsible for the defrost mode.

The bi-metal thermostat is the component that reads the temperature of the actual coil. If it fails, the unit won’t go into defrost mode.

Mechanical and electrical failures

Faulty wiring, a broken switch, refrigerant leak, a burnt compressor – all these things can cause your dehumidifier to freeze up.

Read: What Size Dehumidifier Do I Need For My Crawl Space?

Frigidaire Dehumidifier Freezing Up

Follow these steps to find out what is making your Frigidaire dehumidifier freeze up.

  1. Locate the fan blade and try turning it by hand (it should be turning freely). Ensure that the blade is not rubbing against anything.
  2. Test the motor with a multimeter. If it’s defective, then you would have to replace the fan motor.
  3. Make sure that the blower wheel is turning freely. If the wheel is wobbly, tighten the screw.
  4. Check the air filter. If it looks dirty and clogged – change it.
  5. Ensure that the temperature remains above 65 F or get a dehumidifier that is specifically designed for low temperatures.

Read: What Is Ideal Temperature In The House And Why?

Danby Dehumidifier Freezing Up

Some Dandy dehumidifiers are able to withstand temperatures that are as low as 41 F.

If you have noticed frost on your appliance, simply turn on the fan-only mode until the ice melts.

To make sure that you are not blocking the airflow around the appliance, place the dehumidifier on a smooth, level floor (not on carpeting) and maintain a minimum clearance of at least 16 inches around the air inlets.

Hisense Dehumidifier Freezing Up

Hisense has humidifiers that can operate at very low temperatures (38 F), so the indoor temperature might never become the reason for ice build-up on your unit.

For the models with a back louver, leave around 12-18 inches of space around the back of the unit and its sides. For the devices with top louvers – leave that same amount of space above the dehumidifier. 

Read: Mini Split In Dry Mode Vs. Dehumidifier: Which One Is More Efficient?

Dehumidifier Freezing Up in Basement

Dehumidifiers placed in basements are the units that suffer the most from ice build-up on the coils. This happens because this space in your house is usually cold (unheated basements are around 55 F during winter and spring) and the chances are high that it’s dirty.

Basements are among the dustiest places in practically anyone’s house. No wonder your dehumidifier’s filter will get clogged more often and the coils will eventually get covered in dirt.

By the way, the coils can also freeze up if the relative humidity is low (below 45%). And that’s exactly what may happen, if it is cold in the basement.

If you want your dehumidifier to perform at its best, you should try to keep the basement warm and relatively clean. Or you can simply clean the unit’s coils and change the filter a bit more often.

Hint: the higher you can place your humidifier, the better. Warm moist air usually accumulates near the basement’s ceiling, while the cool dry air that can cause the coils to freeze up ‘falls’ on the floor.

Read: Does A Basement Need Ventilation?

Do Dehumidifiers Have Refrigerant?

There are two different types of dehumidifiers. A desiccant unit does not have refrigerant as it utilizes an absorbent material that extracts the water from the air, while a refrigerant dehumidifier does contain compressed refrigerant.

Actually, the refrigerant is the thing that, in a lot of cases, will cause the coils to freeze up as the temperature of this substance can be very low.

Thanks to this feature, refrigerant-based humidifiers are able to fulfill their main function.

Once the air travels over the coils, it becomes colder. This affects the air’s ability to hold moisture.

As a result, the vapor from the air condenses and drips into a bucket or pan.

Dehumidifier Defrost Sensor – What Is That?

If it is too cold in the room, the water that is condensing inside the unit might immediately freeze. The frost will continue to build up if the dehumidifier is left on.

The defrost sensor is the component that senses the formation of ice on the coil and tells the compressor to stop working. However, the fan is left on, so that the air from the room can contribute to the thawing of the ice.

Why Does My Dehumidifier Says Defrost?

The defrost light indicates that the defrosting cycle has been activated. The device will complete this cycle automatically and your dehumidifier will be ready to operate.

This might happen not only because of low temperature but also due to insufficient airflow or a dirty coil.

How Do I Stop My Dehumidifier from Icing Up?

Check the room temperature

There is an optimum temperature range in which your dehumidifier can efficiently operate (you can find it in the user’s manual).

To find out, if it’s the temperature that’s causing your device to freeze up, place the unit in a warmer room or leave it in the same room but place it a bit higher. 

Move the dehumidifier

Sufficient airflow is crucial for the device’s proper operation. If the unit is freezing up, perhaps, it is too close to the wall or someone placed a box right next to it.

Replace the filter

Check the filter every month or so to ensure that it’s not clogged. Change the filter or wash it every 2-3 months (if you live in a less humid area, you might not have to change the filters more often than every 6 months).

Clean the coils

Turn off the unit and give it some time to cool down. Locate the coils and gently vacuum the top layer of dust; use a soft-bristled brush to get rid of the rest of the dirt.

Read: What Is Proper Humidity For Your House And Why?