Troubleshooting and maintenance

Troubleshooting Dehumidifiers: No Water Collection

Learn how to troubleshoot your dehumidifier if it’s not collecting water, helping eliminate mould and musty smells.

Updated 6 December 2025 Garden Gear Guide guide for UK homes

Dehumidifiers play a vital role in maintaining a healthy indoor environment, especially in homes prone to dampness. If your dehumidifier is not collecting water, it can be frustrating, particularly if you are dealing with visible mould and musty smells. Understanding the potential causes and solutions can help restore your device’s functionality.

This guide will walk you through the common reasons your dehumidifier might not be working effectively and provide practical steps to troubleshoot and resolve the issue.

Understanding How Dehumidifiers Work

Before troubleshooting, it’s essential to understand the basic principles of how a dehumidifier operates. These devices draw in moist air, remove the moisture, and then release drier air back into the room. This process helps to reduce humidity levels and combat mould growth.

Most dehumidifiers use either a refrigerant system or desiccant materials to capture moisture:

  • Refrigerant Dehumidifiers: These use a cooling coil to condense moisture from the air.
  • Desiccant Dehumidifiers: These absorb moisture using a hygroscopic material.

Understanding your device’s mechanism can help you identify issues more effectively.

Common Symptoms of a Non-Collecting Dehumidifier

If your dehumidifier is not collecting water, you may notice several symptoms:

  • The unit is running but not producing condensation.
  • The water tank is empty after an extended period of operation.
  • You can still smell dampness or see mould in the room.

Identifying these symptoms will guide your troubleshooting efforts.

Step-by-Step Troubleshooting Guide

Follow these steps to diagnose and resolve the issue with your dehumidifier:

  1. Check the Humidity Level: Ensure the humidity in the room is above 50%. Dehumidifiers work most effectively in humid conditions. Use a hygrometer to measure the humidity level.
  2. Inspect the Water Tank: Make sure the water tank is correctly positioned. If it’s not seated properly, the unit may not collect water.
  3. Clean the Filter: A clogged filter can restrict airflow, reducing the unit’s efficiency. Remove the filter and clean it according to the manufacturer’s guidelines.
  4. Examine the Coils: If you have a refrigerant dehumidifier, check the coils for frost or ice buildup. This can occur if the temperature is too low in the room. Allow the unit to defrost before restarting it.
  5. Check for Blockages: Ensure there are no obstructions around the intake and exhaust vents. Good airflow is crucial for proper operation.
  6. Look for Leaks: Inspect the water tank and plumbing for leaks. If you notice any, they may prevent water collection.
  7. Test the Humidistat: The humidistat controls when the dehumidifier turns on and off. If it’s faulty, the unit may not operate correctly. Consult a professional if you suspect this component is the issue.

When to Seek Professional Help

If you have followed the troubleshooting steps and your dehumidifier still does not collect water, it might be time to consult a professional. Signs that indicate a need for expert assistance include:

  • Persistent water collection issues despite troubleshooting.
  • Unusual noises or smells from the unit.
  • Frequent error messages or indicator lights.

A qualified technician can diagnose underlying problems and suggest repairs or replacements.

Preventing Future Issues

To avoid problems with your dehumidifier in the future, consider the following tips:

  • Regular Maintenance: Clean the filter and water tank regularly, and check the coils for ice or dirt build-up.
  • Monitor Humidity Levels: Keep an eye on indoor humidity levels, especially during seasonal changes.
  • Proper Placement: Position the dehumidifier in a central location with good airflow around it.

By maintaining your unit and monitoring your environment, you can ensure effective operation and a reduction in dampness.

Frequently asked questions

Why is my dehumidifier not collecting any water?

This could be due to low humidity levels, a full or improperly seated water tank, or a clogged filter. Check these components first.

What should I do if there is ice on the coils?

Turn off the dehumidifier and allow it to defrost. Ensure the room temperature is above the unit’s minimum operating temperature.

Can I use my dehumidifier in a cold room?

Most dehumidifiers are less effective in temperatures below 15°C. Consider using a unit designed for lower temperatures.

How often should I clean the filter?

It’s advisable to clean the filter every few weeks, especially in high-humidity conditions, to maintain airflow and efficiency.

What humidity level should I aim for in my home?

Aim for a relative humidity level between 40% and 60% to prevent mould growth and ensure comfort.

Is it normal for a dehumidifier to make noise?

Some noise is normal during operation, but loud or unusual sounds may indicate a problem that requires inspection.

How can I tell if my dehumidifier is working properly?

Check the humidity levels before and after running the unit. If levels drop consistently and water is collected, it is functioning properly.