Humidifier Filters
Humidifier filters come in two main types: wick filters for portable evaporative humidifiers, and water panels or pads for whole house furnace humidifiers. Both trap minerals as water evaporates and need regular replacement, because a crusted filter evaporates much less water.
What to know
- Match the filter number: for example Honeywell HC-888 (Filter A) for many Honeywell cool moisture models, or Aprilaire #35 for the 600 and 700.
- Change intervals: portable wicks every 1 to 2 months in heavy use, and whole house pads at least once per heating season.
- Hard water shortens filter life. Signs include stiffness, discoloration and white crust.
- Odor or slime means it is time to replace the filter and clean the unit.
- Ultrasonic units: some use demineralization cartridges rather than wicks.
- Compatible vs genuine: check dimensions and material.
Shop Humidifier Wick Filters and Whole House Humidifier Pads.
FAQs
How often should I change a humidifier filter?
For portable evaporative humidifiers, replace the wick every 1 to 2 months in heavy use, or when it becomes stiff, discolored or crusted with minerals. Whole house humidifier pads should be replaced at least once per heating season. Hard water means more frequent changes.
Can you clean and reuse a humidifier wick?
Some manufacturers allow rinsing a wick in cool water to remove loose minerals, which may extend its life slightly. Avoid soaps or bleach unless the manual permits them. Once the wick is stiff, crusted or smells musty, it needs replacing, since cleaning will not restore its absorbency.
Do ultrasonic humidifiers have filters?
Most ultrasonic humidifiers do not use wick filters. Some include an optional demineralization cartridge or ceramic filter to reduce white dust from hard water, which needs periodic replacement. Using distilled water reduces or removes the need for these cartridges and also prevents white dust.