How often should you clean a dehumidifier?

Empty the water bucket whenever it fills (or run a drain hose to a drain), rinse the bucket every few weeks, and clean the air filter every two to four weeks during heavy use. Do a deeper clean of the coils and bucket at the start and end of each humid season. A dehumidifier constantly pulls damp air across cold coils and collects standing water, so it's a prime spot for mold and mildew — regular cleaning keeps it efficient and stops it from blowing musty, moldy air back into the room.

Why does my dehumidifier smell musty?

Because mold or mildew is growing on the coils, in the bucket, or in the drain path where water and dust collect. The unit then circulates that smell into the room. Fix it by washing the bucket with soapy water and a little vinegar or a diluted disinfectant, cleaning or replacing the air filter, gently cleaning the coils, and flushing the drain hose or channel where slime builds up. Letting the bucket sit full of standing water between uses is the most common cause, so empty and dry it when the unit isn't running.

How do you clean dehumidifier coils?

Unplug the unit first. Vacuum the coils gently with a soft brush attachment to remove dust, which insulates the coils and hurts efficiency. For grime, wipe with a cloth dampened with mild soapy water or a coil-safe cleaner, being careful not to bend the thin metal fins — a fin comb straightens any you flatten. Don't soak the electrical components. Clean coils transfer heat and pull moisture far better, so a dusty coil makes the dehumidifier work harder and remove less water.

Can you use vinegar to clean a dehumidifier?

Yes — white vinegar is a good, cheap choice for the bucket and for descaling. Wash the water tank with warm soapy water, then wipe or soak it with a vinegar solution to kill mildew and remove any slimy film, and rinse. Vinegar also helps clear mineral and biofilm buildup in the drain path. For the coils, mild soapy water or a purpose-made coil cleaner is gentler on the fins. Avoid harsh solvents, and never mix vinegar with bleach — the combination releases toxic gas.

Do you need to clean the dehumidifier filter?

Yes — the air filter is the easiest and most impactful part to maintain. Slide it out (usually from the front or top), and every two to four weeks vacuum it or rinse it under water and let it dry fully before reinstalling. A clogged filter chokes airflow, so the unit removes less moisture and works harder, and dust that gets past it fouls the coils. Some filters are replaceable rather than washable; check your manual. A clean filter is the difference between a dehumidifier that keeps up and one that can't.

How to Clean a Dehumidifier (Coils, Bucket, and Filter)

Written & researched by Derek Holt Home & Appliances Editor

Updated August 2026

Close-up detail of the material being worked in a air quality project, in warm late-afternoon light

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Cleaning a dehumidifier takes about 20 minutes and keeps it efficient while stopping it from spreading mold and musty odors. It costs nothing but water, mild soap, and a little vinegar, with no permit or hazard beyond unplugging it first. Because a dehumidifier constantly pulls damp air across cold coils and pools water in its bucket, it’s a natural home for mildew — and it will happily circulate that smell back into your room. The routine is simple: wash the filter and bucket, gently clean the coils, and flush the drain path where slime builds up.

How To Clean and Care For Your Dehumidifier (Frigidaire)

Tools and materials

Mild dish soap and white vinegar for the bucket and drain path, plus a soft cloth and a soft brush.
A vacuum with a brush attachment for the coils and filter, and a fin comb if any coil fins get bent.
Warm water for rinsing. If your unit can’t keep up even when clean, see our best dehumidifier picks.

Golden-hour view of a person adjusting a floor-standing air purifier in a quiet living room

Step 1: Unplug and empty

Switch off and unplug the dehumidifier — never clean it live, given the water involved. Remove and empty the water bucket. If you run a continuous drain hose, disconnect it. Move the unit somewhere you can work on it, ideally near a sink or drain.

Step 2: Clean the air filter

Slide out the air filter (front or top on most units). Vacuum it or rinse it under running water, then let it dry completely before reinstalling. A clogged filter is the most common reason a dehumidifier removes less moisture and runs hard — this two-minute step has the biggest payoff. Replace it instead if yours is the disposable type.

Wide view of a person adjusting a floor-standing air purifier in a quiet living room, in soft overcast light

Step 3: Wash and disinfect the bucket

Wash the water tank with warm soapy water to remove any slimy biofilm, then wipe or soak it with a vinegar solution to kill mildew, and rinse. This is where standing water breeds the musty smell, so don’t skip the disinfecting step. Dry it before reinstalling. Never mix vinegar with bleach.

Step 4: Clean the coils gently

Access the coils (behind the front grille on most units) and vacuum them with a soft brush to lift the dust that insulates them and kills efficiency. For grime, wipe with mild soapy water or a coil-safe cleaner, avoiding the electrical parts. Be gentle — the thin aluminum fins bend easily; straighten any you flatten with a fin comb. Clean coils pull far more moisture.

Wide view of a person adjusting a floor-standing air purifier in a quiet living room, in soft early-morning light

Step 5: Flush the drain path and reassemble

Flush the drain channel and any hose with a vinegar-water solution to clear the slime and mineral buildup that cause smells and blockages. Let everything dry, reinstall the clean filter and bucket, and reconnect the hose. Going forward, empty and dry the bucket when the unit isn’t running so water never sits and breeds mold.

Where to go next

Dehumidifier upkeep pairs with cleaning a humidifier and replacing an air purifier filter for whole-home air health. Chasing a summer musty smell? See why houses smell musty in summer. It all lives under the air quality hub.

We never buy or physically test the products we rank — our picks come from aggregated owner reviews and expert consensus, explained on how we rank. Follow your unit’s manual for coil and filter care.

How to Clean a Dehumidifier