Empty and rinse the tank every three days

The water tank is where bacteria and mineral buildup start. Every three days—or more often if you live in a hard-water area—empty whatever water remains in the tank, rinse it with fresh tap water, and dry it with a clean cloth before refilling. Do not let stale water sit in the tank between uses.

If you see white, chalky deposits inside the tank, that is mineral scale from your tap water. Rinse it away with warm water and a soft brush or cloth. If the deposits are thick, soak the tank in equal parts white vinegar and water for 30 minutes, then scrub gently and rinse thoroughly until no vinegar smell remains.

Key Takeaways

  • Empty and rinse the water tank every three days to prevent bacteria and mold from growing in stagnant water.
  • Clean the filter cartridge or wick according to your model's manual—some are washable, others must be replaced every 30 to 60 days.
  • Soak the base and internal parts in equal parts white vinegar and water for 30 minutes to dissolve mineral buildup, then scrub and rinse completely.
  • Use distilled water instead of tap water to slow mineral scale and reduce how often you need to deep-clean.
  • Let all parts air-dry completely before reassembling to prevent mold from growing inside the humidifier.

Clean or replace the filter or wick cartridge

Honeywell humidifiers use either a replaceable filter cartridge or a washable wick, depending on your model. Check your manual to find out which yours has. If you have a filter cartridge (the model number usually contains HCM or HEV), it typically lasts 30 to 60 days before it needs replacing. If you have a wick, it can be rinsed and reused, but it should still be replaced every season or when it looks discolored or stiff.

To clean a washable wick, hold it under cool running water and gently rinse away any white mineral deposits. Do not soak it or wring it out—just let water run through it. If it is very clogged, soak it in equal parts white vinegar and water for 15 minutes, then rinse thoroughly. Let it air-dry completely before putting it back in the humidifier.

Soak the base and internal parts in vinegar solution

Once a week, disassemble the humidifier and soak the base, fan, and any removable internal parts in a mixture of equal parts white vinegar and water. Let them sit for 30 minutes. This dissolves mineral scale that tap water leaves behind and kills bacteria that can grow on wet surfaces.

After soaking, use a soft brush or old toothbrush to gently scrub away any remaining white deposits, especially around the fan blades and the small openings where mist comes out. Rinse every part thoroughly under running water until you cannot smell vinegar anymore. Vinegar left behind can damage plastic and create an unpleasant smell when the humidifier runs.

Dry all parts completely before reassembling

Moisture left inside the humidifier is where mold grows. After rinsing, stand all parts upright on a clean cloth or paper towel and let them air-dry for at least two hours—longer is better. Wipe down the inside of the base with a dry cloth to remove any remaining water. Do not reassemble or plug in the humidifier until everything is completely dry to the touch.

If you are in a hurry, you can use a clean, lint-free cloth to dry the parts by hand, but air-drying is safer because it reaches into crevices where a cloth cannot. Never use a hair dryer or heat source—the plastic can warp.

Use distilled water to reduce mineral buildup

Tap water contains minerals like calcium and magnesium that build up inside your humidifier and make cleaning harder. Distilled water has these minerals removed, so it leaves far less white scale behind. If you switch to distilled water, you may only need to deep-clean once a month instead of once a week.

Distilled water costs a few dollars per gallon at any grocery store or drugstore. For a humidifier that holds one to two gallons, one jug lasts several refills. The cost of distilled water is usually less than the cost of replacing filters and parts more often because of mineral damage.

Know when to call a professional or replace the unit

If the humidifier leaks from the base, the fan does not spin even after cleaning, or mold appears inside the tank and does not rinse away, the unit may have internal damage that cleaning cannot fix. Honeywell humidifiers are not designed to be repaired by the homeowner—replacement is usually the safer and cheaper option.

If you have cleaned the humidifier thoroughly and it still produces a musty smell or the mist looks discolored, stop using it. Mold or bacteria inside the internal passages cannot be reached by soaking, and running the humidifier will spread those organisms into your home's air.

Frequently Asked Questions

Can I use bleach to clean my Honeywell humidifier?

No. Bleach can damage the plastic parts and leave toxic residue that will be released into the air when the humidifier runs. White vinegar is safer and just as effective at killing bacteria and dissolving mineral scale.

How often should I clean the humidifier if I use distilled water?

Empty and rinse the tank every three days, and do a deep soak of the base and parts once a month. If you use tap water, increase the deep cleaning to once a week. Hard water areas may need cleaning twice a week.

What if white powder comes out of the mist?

That is mineral dust from scale inside the humidifier. Soak the base and filter in vinegar solution for 30 minutes, scrub all parts, and rinse thoroughly. Switch to distilled water going forward to prevent it from happening again.

Can I put the filter cartridge in the dishwasher?

No. Dishwasher heat and detergent can damage the filter material. Rinse it gently under cool running water only. If it is a replaceable cartridge, it is cheaper to replace it than to risk damaging it in the dishwasher.

Is it safe to use the humidifier while parts are still drying?

No. Moisture trapped inside creates an environment where mold grows quickly. Always wait until all parts are completely dry before reassembling and plugging in the unit.