Dehumidifier not collecting water

Symptoms

• Unit runs but the tank stays empty or nearly empty
• Room still feels damp
• Humidity reading doesn't drop
• Fan blows but nothing seems to happen

Likely causes

• CommonRoom humidity or temperature already too low for the unit to work efficientlyMost compressor dehumidifiers struggle to pull water below about 65F or already-moderate humidity.
• CommonDirty air filter blocking airflow over the coilRestricted airflow means less air contacts the cold coil, so less moisture condenses.
• CommonHumidistat set too highIf the target humidity is set above the room's current level, the unit may barely run.
• PossibleLow refrigerant chargeA coil that isn't getting cold enough won't pull moisture from the air even with good airflow.
• Less commonCompressor not engagingFan runs, but no cooling hum means the compressor may have failed.

What to do

1. Check the humidistat setting and lower it well below the current room humidity so the unit runs continuously for testing.
2. Remove and clean the air filter, then let it dry before reinstalling.
3. Move the unit to a warmer part of the room if it's in a cold basement corner, since most units need reasonably warm air to work well.
4. Let the unit run for at least an hour and check whether the coil (visible with the front cover off) feels cold and slightly wet.
5. Listen for the compressor's low hum in addition to the fan noise; fan-only sound with no hum suggests the compressor isn't starting.
6. If the coil never gets cold and wet after an hour of running, suspect low refrigerant or a compressor fault.

Tools and parts

• None

When to call a pro

Call an appliance technician if the compressor isn't running or the coil never gets cold, since that points to an electrical or refrigerant fault.

Safety