Why Is My Dehumidifier Freezing Up?

In the pursuit of comfort and well-being, our homes often become our sanctuaries. And just like any guardian of a sanctuary, ensuring its health and functionality becomes paramount.

I’m Mannan Wasif, your guide through the labyrinth of tricks and troubles related to dehumidifiers. Today, let’s delve into a common conundrum that has left homeowners scratching their heads: why is my dehumidifier freezing up, leaving you perplexed and longing for its efficient service?

Picture this: a cozy evening at home, the air just right, and your dehumidifier humming in the background, dutifully battling excess moisture. Suddenly, it happens—the once-reliable appliance transforms into an icy enigma. You’re not alone in this puzzling scenario, and you’re certainly not alone in your quest for answers.

So, join me as we embark on a journey to unravel the mysteries of dehumidifiers and understand the science behind their occasional frosty episodes. Together, we’ll uncover the causes, solutions, and preventive measures to ensure your dehumidifier continues to serve as a steadfast guardian of your home’s comfort and health.

Let’s warm up to the topic, quite literally, and find out why your dehumidifier is freezing up.

Why is my dehumidifier freezing up?

As the moisture hits the condenser coils, it becomes ice rather than liquid water, and the dehumidifier freezes up. Your unit may do this for a variety of reasons. There are eight most common causes of this problem.

1. Low Temperatures

It’s generally recommended to use portable dehumidifiers in rooms above 65 degrees Fahrenheit. In colder temperatures, condensation on the coils can turn to ice, leading to a cascade effect of ice buildup and eventual shutdown.

Ensure that you place your dehumidifier in warmer areas of your home if the temperature falls below this threshold.

2. Poor Air Flow

Proper airflow is crucial for dehumidifiers to function correctly. Air moving through the coils prevents them from getting too cold. Clean or replace the filter to prevent airflow obstructions, and make sure there’s at least 6 inches of space around the air intake and exhaust areas.

The dehumidifier, a key component in open-cycle liquid desiccant air conditioning systems, was experimentally assessed in a solar thermally driven, low-flow, falling-film configuration at Queen’s University. The tests revealed significant variations in desiccant concentration, leading to the discovery of a relationship between desiccant concentration and dehumidification rate. Inlet-air humidity was identified as a significant factor, with a moisture removal rate ranging from 1.1 g/s to 3.5 g/s and an average dehumidification effectiveness of 0.55.

3. Dirty Coils Or Fan

Even with a well-maintained filter, finer particles like dust and dirt can accumulate on the coils and fan, reducing their effectiveness. Unplug your dehumidifier, remove the coils and fan, and clean them thoroughly to remove any dirt or grime.

4. Broken Blower Wheel

The blower wheel, a critical component of the fan system, can accumulate debris or malfunction, leading to coil freezing. Clean and inspect the blower wheel to ensure proper airflow.

5. Broken Fan Motor

A malfunctioning fan motor can result in weak airflow or no airflow at all. Test the fan motor by running the unit with the fan only, and if it’s making unusual noises or not working, consider replacing it.

6. Faulty Humidistat

A malfunctioning humidistat can cause the compressor to run continuously, fostering ice formation. Employ a separate hygrometer to cross-check the room’s humidity level. If it deviates from the dehumidifier’s reading, you likely have a faulty humidistat.

7. Malfunctioning Bi-Metal Thermostat

Some dehumidifiers feature bi-metal thermostats that regulate compressor operation based on evaporator temperature. A malfunctioning thermostat can trigger compressor operation despite ice buildup on the coils.

8. Low Or Depleted Refrigerant

Like other cooling appliances, dehumidifiers use Freon to cool condenser coils. Over time, leaks can deplete refrigerant levels, resulting in freeze-ups. If you suspect this, enlist a professional for a recharge.

How to fix a dehumidifier that is freezing up?

Your understanding of the causes of dehumidifier icing should be complete by now. The purpose of this section is to explain how to troubleshoot them one by one.

1. Increase the room temperature 

This step is crucial because dehumidifiers are generally designed to work optimally at temperatures above 65 degrees Fahrenheit. When the room is colder than this, the moisture on the coils can freeze, causing the unit to malfunction.

By raising the room temperature, you create an environment where the dehumidifier can operate effectively without freezing up.

2. Clean or replace the air filter 

The air filter in your dehumidifier prevents dust, dirt, and other particles from clogging the coils and fan. Over time, the filter can become dirty and impede airflow, leading to freezing issues.

Cleaning or replacing the air filter ensures that air can flow freely through the unit, preventing ice formation on the coils.

3. Repair the restricted fan blade or blower wheel

The blower wheel and fan are critical components responsible for moving air over the coils. If these components become dirty or obstructed by debris, they can’t function properly, which can lead to freezing.

By inspecting and cleaning the blower wheel and fan, you ensure that they can operate efficiently, allowing proper airflow and preventing ice buildup.

4. Fix or replace the fan motor

The fan motor is responsible for powering the fan and maintaining airflow within the dehumidifier. If the fan motor is malfunctioning or not working correctly, it can result in weak or no airflow, contributing to freezing issues.

Testing the fan motor by running the unit with the fan alone can help identify if it’s the problem. If the motor is faulty, it should be replaced to restore proper functionality.

5. Test and replace the humidistat or thermostat

The humidistat and thermostat play a crucial role in regulating the dehumidifier’s operation based on humidity levels and temperature. If either of these components is malfunctioning, it can cause the unit to run excessively or inadequately, leading to freezing.

Examining and, if necessary, replacing these components ensures that they accurately control the dehumidifier’s operation and prevent ice buildup.

When temperature and airflow aren’t the cause

The humidity sensor or refrigerant could be malfunctioning if temperature and airflow are not the problem. As a result, you’ll cross the line from “everyday maintenance” and will probably want to consider a professional repair or replacement quote, a DIY fix, or a DIY repair.

1. Your humidistat could be damaged

The humidistat in a dehumidifier functions similarly to a thermostat but measures and controls humidity levels. When functioning correctly, it ensures that the dehumidifier only operates when the humidity level exceeds the set target. If the humidistat is damaged or malfunctioning, it may incorrectly sense humidity levels, causing the dehumidifier to run continuously even when not needed.

This prolonged operation can lead to excessive cooling, ice formation on the coils, and ultimately the freezing of the unit. To diagnose this issue, you can listen for a clicking sound when adjusting the humidity settings or use a multimeter to test its functionality. If it’s faulty, replacement is typically recommended.

2. Your refrigerant might be low

Dehumidifiers, like air conditioning systems, use a refrigerant (often Freon) to cool the coils and remove moisture from the air. When the refrigerant level becomes low, it can disrupt the cooling process, leading to inadequate moisture removal and the potential freezing of the coils. Low refrigerant levels can result from leaks within the system, especially in older units.

Besides causing ice formation, low refrigerant levels can also damage the coils themselves. To check for this issue, it’s advisable to consult a qualified HVAC professional who can assess the refrigerant levels, identify any leaks, and recharge the system if necessary.

Preventive Dehumidifier Maintenance for Trouble-Free Operation

To ensure your dehumidifier runs smoothly and efficiently while preventing freezing issues, proactive maintenance is key. Regular maintenance not only extends the lifespan of your unit but also helps maintain indoor air quality. Here’s a guide to essential maintenance practices and cleaning schedules:

1. Clean or Replace Air Filter

The air filter is your dehumidifier’s first line of defense against airborne particles. Over time, it can become clogged with dust, pet dander, and other contaminants, hindering airflow. To maintain optimal performance, check the filter monthly and clean or replace it as needed. Washable filters can be rinsed under running water with mild soap and left to air dry. For non-washable filters, consult your unit’s manual for replacement guidelines.

2. Clean the Water Collection Container

The water collection container in your dehumidifier can accumulate mineral deposits and mold over time. Empty and clean it regularly to prevent mold growth and maintain a healthy indoor environment. Use a mixture of warm water and a mild detergent to clean the container, and thoroughly rinse and dry it before reinserting it into the unit.

3. Inspect and Clean the Coils and Fan

Over time, dirt and debris can build up on the coils and fan, reducing efficiency and airflow. Unplug your dehumidifier and remove the coils and fan for inspection and cleaning. Use a vacuum cleaner with a brush attachment to remove loose dirt and debris. If stubborn grime remains, wipe down the components with a damp cloth. This practice should be performed at least once a season or more frequently if you notice reduced performance.

4. Check the Drainage System

If your dehumidifier has a continuous drainage system, ensure that the hose or drainage path is clear and free from obstructions. This prevents water from backing up into the unit, which can lead to freezing issues. Periodically inspect the drainage system and clear any blockages.

5. Examine the Humidistat and Thermostat

Test the accuracy of your dehumidifier’s humidistat and thermostat settings. Use a separate hygrometer to measure the room’s humidity levels and compare them to your unit’s readings. If there’s a significant discrepancy, consider recalibrating or replacing these components.

6. Inspect the Power Cord and Plug

Ensure that the power cord and plug are in good condition. Look for signs of wear or damage, such as frayed wires or exposed conductors. Damaged cords and plugs can pose safety hazards and affect your dehumidifier’s operation.

7. Professional Inspection and Service

Periodically, consider having your dehumidifier professionally inspected and serviced. A trained technician can identify and address potential issues before they lead to freezing problems. This is especially important for older units or those in high-humidity environments.

Conclusion

In summary, if your dehumidifier persists in freezing up, ensure adequate room heating and ventilation. Regularly clean or replace filters and inspect for any obstructions. Follow the outlined troubleshooting steps, and your dehumidifier should soon be back to optimal performance. Should you have further queries, don’t hesitate to reach out.