Dehumidifier Blues Why It Ices Up and How to Fix It

Ah, the dehumidifier. Your trusty warrior against moisture, mold, and mildew. But what happens when the tables turn and your dehumidifier itself gets frosty? Don’t worry, a frozen dehumidifier isn’t necessarily broken. Here’s why it happens and how to get it back in fighting shape.

Did you know? While a dehumidifier’s main function is to combat moisture and mold, it can also indirectly improve your health. Excess moisture can create a breeding ground for dust mites, allergens, and even some respiratory illnesses. By reducing humidity levels, dehumidifiers can help create a healthier indoor environment.

Why Does My Dehumidifier Get Icy?

A detailed image showing a dehumidifier undergoing a defrosting process. The dehumidifier is turned off and placed in a warm, dry room with a comfortable and inviting atmosphere.

The main culprit is usually cold temperatures. Dehumidifiers work by drawing in moist air, condensing the moisture onto cold coils, and collecting the water in a reservoir. But if the room temperature dips too low (below 60°F is a common threshold), the coils can get too cold. Instead of condensing, the moisture freezes, creating a frosty nightmare.

Here are some other potential causes:

  • Airflow blockage: If the dehumidifier is crammed in a corner or the air filter is clogged, airflow is restricted. This prevents proper condensation and can lead to icing.
  • Dirty coils: Dust and grime buildup on the coils can also hinder condensation and contribute to freezing.
  • A full or clogged drain hose: A clogged or disconnected drain hose can prevent collected water from draining properly, leading to ice buildup around the drain outlet.

Tip: When possible, open windows and allow natural sunlight to dehumidify your space. This is a free, eco-friendly way to reduce moisture levels and give your dehumidifier a break, especially during warmer months.

Fixing Your Frozen Dehumidifier


  1. Defrosting is Key: The first step is to give your dehumidifier a chance to thaw. Turn it off and let it sit for 24 hours in a warm, dry place. Don’t try to force the defrosting process, such as using a hairdryer, as this can damage the unit.

  2. Temperature Matters: Once defrosted, ensure the room temperature is above 60°F (ideally between 60°F and 80°F). If your basement is constantly chilly, consider relocating the dehumidifier to a warmer part of the house or using a model designed for cold environments. These models typically have lower operating temperature thresholds.

  3. Clear the Airflow Path: Make sure there’s at least a foot of clearance around the dehumidifier on all sides. This allows for proper airflow. Also, clean the air filter according to the manufacturer’s instructions. A clogged filter restricts airflow and can lead to icing.

  4. Clean the Coils: Over time, the coils can accumulate dust and debris. Consult your user manual for cleaning instructions. Some recommend using a soft brush or vacuum cleaner attachment, while others suggest a gentle coil cleaner. Never use abrasive cleaners or shove sharp objects into the coils.

  5. Inspect the Drain Hose: A clogged or disconnected drain hose can prevent collected water from draining properly, leading to ice buildup. Make sure the hose is clear and securely attached to the dehumidifier and drain.

Tip: Many dehumidifiers come with a humidity control setting. Instead of running the unit continuously, set it to automatically maintain a specific humidity level (usually between 30% and 50%). This prevents the dehumidifier from overworking and potentially reaching temperatures that cause freezing.

Preventing Icy Meltdowns

An image depicting a well-maintained dehumidifier in a properly ventilated room. The dehumidifier is positioned with ample space around it, indicating good airflow.

Dehumidifiers are lifesavers in humid environments, but frosty malfunctions can leave you with a puddle of a different kind. Here’s a deeper dive into preventing icy meltdowns and keeping your dehumidifier running smoothly:

Maintaining a Warm Oasis

  • Temperature is Key: Aim for a room temperature above 60°F (15.5°C) for optimal dehumidifier performance. Cold temperatures can hinder the dehumidification process and lead to ice buildup.
  • Mind the Season: During colder months, avoid using the dehumidifier in unheated spaces like basements or crawlspaces. Consider alternative solutions like portable heaters to raise the ambient temperature before running the dehumidifier.

Cleaning is King (and Queen)

  • Filter Finesse: Regular air filter cleaning is crucial. A clogged filter restricts airflow, making the dehumidifier work harder and potentially causing the coils to freeze. Refer to your user manual for the recommended cleaning frequency – weekly or bi-weekly cleaning is common.
  • Coil Care: Don’t neglect the coils! Dirty coils, like dirty filters, can impede airflow and contribute to freezing. Following the manufacturer’s instructions, clean the coils regularly using a soft brush or vacuum cleaner attachment. Be gentle to avoid damaging the delicate fins.

Did you know? While basements are a common target for dehumidifiers, they can be beneficial in other areas of your home as well. Do you have a laundry room that constantly feels damp? Or a bathroom prone to mildew buildup around the shower? Dehumidifiers can help control moisture levels in these areas and prevent moisture-related problems.

Emptying the Reservoir: Don’t Let it Overflow!

An illustration of a dehumidifier with an empty, well-maintained water reservoir. The image shows the dehumidifier in a clean, organized environment. The reservoir is clearly visible and empty, indicating regular emptying and maintenance

  • Reservoir Responsibility: An overflowing reservoir can lead to leaks and potentially affect surrounding components, including the coils, which could contribute to freezing. Make emptying the reservoir part of your maintenance routine. Consult the user manual for proper disposal instructions – some dehumidifiers connect directly to a drain hose for continuous drainage.

Humidity in Harmony

A cozy, home interior setting with a hygrometer prominently displayed, showing a balanced humidity level.

  • Find the Balance: Dehumidifiers are designed to maintain a specific humidity level, typically between 30% and 50%. Running the dehumidifier continuously, especially in colder environments, can lead to over-dehumidification, causing the coils to become too cold and freeze.
  • Monitor and Modify: Invest in a hygrometer to measure humidity levels. Adjust the dehumidifier settings to maintain the desired humidity level and prevent the unit from overworking.

When in Doubt, Call in the Experts:

If you’ve followed these steps and your dehumidifier is still experiencing freezing issues, don’t hesitate to consult a qualified technician. They can diagnose the problem and perform any necessary repairs to get your dehumidifier back in top shape.

By following these tips and maintaining your dehumidifier, you can keep it running smoothly and prevent future icy blockages, ensuring a comfortable and moisture-free environment.

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