9 Common Reasons & Fixes
If your dehumidifier is running but the water tank stays empty, something isn’t working correctly. The good news: in most cases, the problem is simple and fixable.
This is the most common reason. Dehumidifiers only collect moisture when indoor humidity is above about 50–55%.
Signs:
Fix:
Use a hygrometer (many units display humidity in the app or on screen). If humidity is already low, the machine is working properly.
Most standard compressor dehumidifiers work best between 15°C – 30°C. If your basement or room is below 15°C, the coils may freeze and stop extracting moisture.
Signs:
Fix:
Raise room temperature, or use a desiccant dehumidifier (better for cold rooms).
A clogged air filter restricts airflow, reducing moisture extraction.
Signs:
Fix:
Remove filter, wash with warm water, let dry completely before reinstalling. Clean every 2–4 weeks.
If the tank isn’t fully inserted, the machine may stop collecting water or shut off entirely.
Fix:
Remove and reinsert the tank firmly until it clicks. Some units will show a warning light if the bucket is misaligned.
If you use a drain hose instead of the tank, the hose may be kinked, clogged, or not angled downward.
Signs:
Fix:
Ensure a downward slope, check for blockages, and clean the hose regularly.
If you only hear the fan but no deeper compressor sound, the compressor may not be activating.
Signs:
Fix:
Set humidity target lower (e.g., 40%) and wait 5–10 minutes. If still no compressor noise, professional service may be required.
Many modern dehumidifiers pause operation to prevent ice buildup. This is normal in cooler environments.
Signs:
Fix:
This is normal behaviour. Wait for the defrost cycle to complete. If it happens constantly, the room may be too cold for a compressor unit.
If your dehumidifier capacity is too low, it may run continuously but collect very little water. For example, a 10L/day unit won’t handle a damp 40m² basement effectively.
Fix:
Choose the proper capacity for your room size (see table below).
If humidity is high (60%+), room temperature is normal, the filter is clean, and the compressor still doesn’t start — the unit may have a mechanical fault.
Signs:
Fix:
Contact the manufacturer for warranty service or professional repair.
Choosing the right capacity prevents underpowered operation and ensures effective moisture removal.
| Room Size | Recommended Capacity |
|---|---|
| 10–20 m² | 10–12L / day |
| 20–35 m² | 12–16L / day |
| 35–50 m² | 16–20L / day |
| Basement / Very Damp | 20L+ |
This depends on the humidity level in your room. In a damp room (65–75% humidity), a 10–20L unit may collect 1–3 litres per day initially. In very damp basements, expect 5+ litres daily.
If you are only getting a few drops, something is likely wrong — unless humidity is already low.
Most issues are solved in 5–10 minutes.
It’s over 5–7 years old
Compressor doesn’t activate
It struggles in large spaces
Energy consumption is high
Modern units are quieter, more energy efficient, and come with smart features like app control and auto-drainage.
Related Guide
Looking to upgrade? See our full comparison of the best dehumidifiers for homes, apartments, and basements.
In most cases, your dehumidifier is not collecting water because:
Only rarely is it a serious mechanical issue. Start with the simple fixes above before assuming the unit is broken.
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