How to clean a dehumidifier, tank and filter

What you need

Avoid bleach, solvents and abrasive cleaners unless the manual specifically allows them. They can damage plastics, the tank float and coil coatings.

• A soft brush or the brush attachment on a vacuum
• Lukewarm water and a little mild washing-up liquid
• A soft cloth
• A bottle brush for the tank, if it has awkward corners
• Your manual

Monthly filter wash

Every few weeks in heavy use is a sensible interval. A clogged filter cuts airflow, which reduces extraction and can make a compressor unit ice up. If your model has a HEPA or carbon filter as well, these usually cannot be washed and need replacing at the interval the maker gives.

1. 1

   Switch off and unplug the dehumidifier.

2. 2

   Remove the filter, usually from the back or side grille.

3. 3

   Vacuum loose dust off with a brush attachment.

4. 4

   Rinse in lukewarm water with a little mild washing-up liquid if it is greasy.

5. 5

   Rinse clean and shake off excess water.

6. 6

   Let it dry completely at room temperature, out of direct heat.

7. 7

   Refit the filter before switching on.

Rinsing the tank

Standing water in the tank can develop a slimy film and a stale smell. Empty the tank regularly rather than leaving water in it for days, and rinse it with warm water. Every few weeks, add a little mild washing-up liquid, swish or brush it round, then rinse thoroughly so no residue is left.

Take care around the float, the small part that tells the unit when the tank is full. Do not pull or bend it; if it sticks, the unit may stop or show a full-tank warning. Let the tank dry before refitting if you are storing the unit.

Coils, grilles and the outside

Look at the coils through the filter opening with a torch. A light layer of dust can be removed carefully with a soft brush or vacuum brush from the outside. Do not push anything between the fins, which are thin and bend easily, and do not spray water into the unit.

Wipe the outer case and grilles with a damp cloth. Vacuum the air inlet and outlet grilles if dust collects there. If the coils are heavily soiled or frosted regularly, that is a job for the maker's service team rather than a home clean. See why a dehumidifier ices up for common causes.

Note:Always unplug before cleaning. Never spray water into the unit or use it until every part you have washed is completely dry.

Cleaning schedule

If the unit sits unused over summer, clean it, dry it, and store it upright with the tank empty. Many models have a drying function that runs the fan to dry the inside before storage.

When cleaning does not fix it

If the unit still smells musty after cleaning, check the drain hose too, if you use one, and flush it with warm water. If it is collecting little water, see dehumidifier not collecting water for checks such as room temperature and humidity target. For Meaco models specifically, our Meaco how-to guide covers settings.

Best dehumidifiers for UK homes →

Frequently asked questions

How often should I clean my dehumidifier filter? Every few weeks in heavy use, or as the manual says. A clogged filter cuts airflow and extraction.

Can I use vinegar or bleach to clean the tank? Check your manual first. Mild washing-up liquid and warm water is the safe default; some cleaners can damage plastics and the float.

Why does my dehumidifier smell? Usually water left standing in the tank or a dusty filter. Empty and rinse the tank, wash the filter, and let everything dry.