Empty and rinse the tank weekly

The water tank is where mineral buildup and mold grow fastest. Once a week, unplug the humidifier, remove the tank from the base, and pour out any remaining water. Rinse the inside of the tank under running water, using your hand or a soft cloth to wipe the walls. Do not use abrasive scrubbers or scouring pads—they scratch the plastic and create places for bacteria to hide.

If you see white, chalky deposits (mineral scale), fill the tank halfway with equal parts white vinegar and distilled water. Let it sit for 30 minutes, then scrub gently with a soft brush or cloth and rinse thoroughly under running water until the vinegar smell is gone. Repeat this step every two to four weeks, depending on how hard your tap water is.

Key Takeaways

  • Empty and rinse the water tank every week, and soak it in vinegar and distilled water every two to four weeks to remove mineral scale.
  • Clean the ultrasonic membrane at the base of the humidifier monthly by dipping a cotton swab in vinegar and gently wiping the small metal disc.
  • Use distilled water instead of tap water to slow mineral buildup and reduce the frequency of deep cleaning.
  • Replace the filter cartridge (if your model has one) according to the manual, usually every one to three months depending on water hardness.
  • Never submerge the base unit or motor in water—only the removable tank and filter cartridge should be wet-cleaned.

Clean the ultrasonic membrane monthly

The ultrasonic membrane is a small metal disc at the bottom of the base unit where the mist is actually created. Mineral deposits here reduce mist output and can eventually stop the humidifier from working. Once a month, unplug the unit and let it cool for at least 15 minutes.

Dip a cotton swab in white vinegar and gently wipe the metal disc. Do not scrub hard or use anything sharp—the membrane is delicate and damage will require replacement. Wipe away any vinegar residue with a dry cotton swab. Let the base air-dry completely before plugging the humidifier back in.

Replace the filter cartridge on schedule

Many HoMedics models include a replaceable filter cartridge that catches minerals before they reach the tank. Check your manual for your specific model number to find the replacement schedule—it typically ranges from one to three months depending on water hardness and how often you run the unit.

To replace it, unplug the humidifier, remove the tank, and locate the cartridge (usually a small cylinder near the base). Slide or unscrew it according to your manual and insert a new one. Using the correct replacement part matters: HoMedics sells model-specific cartridges, and using the wrong size reduces cleaning effectiveness.

Switch to distilled water to reduce buildup

Tap water contains minerals like calcium and magnesium that create white scale inside the tank and on the ultrasonic membrane. Distilled water has these minerals removed, so it produces far less buildup. If you use distilled water from the start, you may only need to deep-clean the tank every four to six weeks instead of every two to four weeks.

Distilled water costs a few dollars per gallon at any grocery store or pharmacy. For a humidifier that runs eight hours a day, one gallon lasts about three to five days. The small cost is worth it if your tap water is hard or if you want to spend less time cleaning.

Clean the mist outlet and cap

The opening where mist comes out can collect mineral dust and reduce output. Once a month, wipe the mist outlet with a damp cloth or soft brush. If mineral buildup is visible, dip a cotton swab in vinegar and clean the opening gently, then wipe dry.

The cap that covers the outlet when the humidifier is off should also be rinsed weekly under running water. A clogged cap traps moisture and encourages mold growth inside the unit.

Never submerge the base or motor

The base unit contains the motor, heating element (if your model has one), and electrical connections. Water inside the base will cause the humidifier to fail or become a shock hazard. Only the removable tank, filter cartridge, and mist cap should be wet-cleaned.

If you spill water on the base, unplug the unit when ready and let it dry completely—at least 24 hours in a warm, dry room—before plugging it back in. If water gets inside the motor housing, the humidifier will need professional repair or replacement.

Troubleshoot low mist output

If your humidifier suddenly produces less mist, mineral scale on the ultrasonic membrane is usually the cause. Clean the membrane with a vinegar-soaked cotton swab as described above. If mist does not return after cleaning, the membrane may be damaged and will need replacement—contact HoMedics customer service with your model number for a replacement part.

Low output can also mean the tank is not seated properly on the base. Remove the tank, check that the connection points are clean and dry, and reseat it firmly until you hear or feel it click into place. If the tank is cracked or warped, it may not seal correctly and will need replacement.

Frequently Asked Questions

Can I use tap water if I clean more often?

Yes, but it is not ideal. Tap water will still leave mineral deposits even with weekly cleaning. If you must use tap water, plan to deep-clean the tank and membrane every one to two weeks instead of every four weeks. Distilled water is inexpensive and saves you time in the long run.

What if vinegar smell lingers after cleaning?

Rinse the tank multiple times under running water until you cannot smell vinegar anymore. Fill the tank with fresh distilled water, run the humidifier for five minutes over a sink or bathtub, then empty and rinse again. The smell will fade once the unit runs with clean water.

How do I know if the ultrasonic membrane is damaged?

A damaged membrane will produce no mist at all, even after cleaning. If the humidifier runs but creates no visible mist and cleaning does not restore output, the membrane has likely failed. You will need to order a replacement membrane for your specific model from HoMedics or an authorized retailer.

Is it safe to use vinegar inside the humidifier?

Yes. White vinegar is safe for cleaning the tank, membrane, and removable parts. Always rinse thoroughly with distilled water afterward to remove all vinegar residue before running the humidifier. Never pour vinegar into the base unit or motor housing.

What should I do if mold appears inside the tank?

Empty the tank, fill it halfway with equal parts white vinegar and distilled water, and let it soak for one hour. Scrub the inside gently with a soft brush, rinse thoroughly, and dry completely before refilling. If mold returns quickly, you may be leaving water in the tank between uses—always empty it after each session to prevent mold growth.