The short answer
Empty and rinse the tank daily, descale with white vinegar weekly, disinfect with the maker's recommended product, rinse thoroughly, and dry everything before storing it.
Daily
- Empty the tank and base; don't top up old water.
- Rinse and let the parts air-dry if you'll skip a night.
- Refill with fresh water (distilled for ultrasonic units).
Weekly
- Unplug the unit.
- Fill the tank and base with undiluted white vinegar and let it stand 20 to 30 minutes to dissolve scale.
- Scrub with a soft brush; on ultrasonic units, wipe the transducer gently, never scrape it.
- Rinse until the vinegar smell is gone.
- Disinfect only as the maker allows (some approve diluted bleach or hydrogen peroxide), then rinse thoroughly.
SafetyNever mix vinegar and bleach. Never run a cleaning solution through the humidifier into the room.
Wicks and filters
Evaporative wicks can't be cleaned back to new; replace them when they stiffen, discolor or smell. Demineralization cartridges in ultrasonic units are replaced on the maker's schedule.
End of season
Clean and disinfect, discard the wick, dry every part completely and store the unit with the tank open.
Products mentioned
Questions readers ask
Can I clean a humidifier with vinegar?
Yes, white vinegar is the usual descaler; rinse it out completely before running the unit.
What happens if you don't clean a humidifier?
Scale builds up and bacteria or mold can grow in the water and be sprayed into the room.