Free Shipping on orders over $99 | FREE 365-DAY RETURNS
Filters Fast Logo Header

AprilAire 45 Replacement Water Panel Humidifier Filter - 2-Pack

Aprilaire 45

Only $19.98 per Filter
Retail: $49.99 /ea
You Save: 20%
As low as
Retail: $49.99
You Save: 20%
in stock
Ready to Ship! Home Filter Club
Subscribe & Save

Subscribe and save with the Home Filter Club! Find your filter, choose how often you want it delivered, and we’ll do the rest!

Never run out of filters during the season with the AprilAire 45 Replacement Water Panel Humidifier Filter - 2-Pack. As a key component in generating humidity in your AprilAire 400 humidifier system, the AprilAire 45's filter media absorbs water from the tray while a fan pushes air across the material. This creates moisture in the air which covers the entire room! AprilAire recommends replacing the AprilAire 45 every 6-12 months for optimal performance and efficiency.


  • Brand: AprilAire
  • Part Number: AprilAire 45
  • Pack Size: 2
  • Filter Life: 6 - 12 Months
  • Dimensions: 10" x 12-3/4" x 1-3/4"

How do you install the AprilAire 45?

  1. Note humidifier control setting and turn dial to the OFF position.
  2. Move bypass damper to summer position.
  3. Press the tabs at top and bottom and pull cover off base.
  4. Clean distribution tray per instructions. Clean scale control insert using vinegar solution.
  5. Remove old AprilAire 45 water panel.
  6. Inspect the plastic feed tube by gently flexing it and looking for cracks or signs of wear. Replace tube if it is cracked, brittle, or has been damaged.
  7. Re-insert the Water Panel Evaporative Assembly color side up and snap cover back on.
  8. Connect drain line. If drain line cannot be cleaned, replace ADHC: (Automatic or Manual mode).
  9. Check system operation by turning the knob to TEST. With furnace blower operating, humidifier will operate for one minute.

How often should you replace the AprilAire 45?

  • Changing your AprilAire 45 is a very quick and easy process that should be done once every six to twelve months.

What contaminants does the AprilAire 45 reduce?

  • The AprilAire 45 reduces the formation of the following contaminants:

    • Bacteria
    • Viruses
    • Fungi
    • Dust Mites

Compatible Models:

The AprilAire 45 Replacement Water Panel Humidifier Filter - 2-Pack is correct replacement for the following model numbers:

BrandModel NumberDescription
Aprilaire 400 Humidifier Filter
Aprilaire 400A Humidifier Filter
Aprilaire 400M Humidifier Filter
Aprilaire 4788 MAINTENANCE KIT Humidifier Filter
No results for {X}


Customer Reviews:

Total Reviews: 8 | Average Rating: 4.6 / 5.0

Martin Gottlieb2023-05-26

I've been using this filter for many years. And it works fine. Just got a new humidifier yesterday and it's in April air and uses these filters as well. So I'll be continuing to use these for many years to come.

Collected by
Cynthia Padgett2023-01-14

Was just what was described in description. Fit my humidifier perfectly.

Collected by
Jack Willmarth2022-03-07

Love my humidifier and these panels catch a lot of crap.

Collected by

Great product.

Collected by

It works fine.

Collected by
Kenneth Carlson2022-01-20

No additional information

Collected by

It’s fine for what it does. There are other brands that are readily available in big box stores that will do the same thing.

Collected by
Margaret Loennecker2021-11-16

Exactly what I wanted

Collected by

Product Availability

Please provide your e-mail address below to receive a notification when this product becomes available:


Thanks! We'll send you a notification when this product is available!