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

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!

Free Shipping Item Banner

Aprilaire 4640 Humidifier Scale Control Insert 10-Pack


Only $19.99 per Insert
$19.99 /ea
Retail: $24.99 /ea
You Save: 20%
As low as
Retail: $24.99
You Save: 20%
Special Order. Ships in 5 to 6 business days.
Home Filter Club

Sign up for the Home Filter Club in checkout. You choose how often you want your filter, and we take care of the rest. Home Filter Club
Purchasing for a Business?

Contact [email protected] to gain access to case quantity discounts, account management and terms! Home Business Services

The Aprilaire 4640 is the correct replacement for the following humidifiers:

  • Aprilaire 500
  • Aprilaire 500A
  • Aprilaire 500M

The Aprilaire 4640 Humidifier Scale Control Insert is for use in your 500 series model humidifier. This Aprilaire humidifier scale control is a U-shaped piece that encases your humidifiers water panel evaporator.

The Aprilaire 4640 Specifications:

  • Contains 1 humidifier scale control insert
  • Works with your 500 series model humidifier
  • Item Weight: 4.8 ounces

The Aprilaire humidifier scale control will direct mineral build up back into your humidifiers evaporative pad, keeping it out of your clean, humidified air. This humidifier scale control is a key feature to keeping your Aprilaire 500 series model humidifier working at peak performance.


Customer Reviews:

Total Reviews: 8 | Average Rating: 4.8 / 5.0

The filter's work and fit well in my humidifier.

Collected by

It was easy to order just what I needed and it came right to my door.

Collected by

They seem to be working ok.

Collected by


Collected by

Great product and customer service.

Collected by

This is a great product .

Collected by

Very expensive

Collected by

The best price and high quality make this a no-brainer!

Collected by