Skip to content

FREE SHIPPING ON ORDERS OVER $50

My Account

Contact Customer Support: 888.623.4678

Furnace Filters
Humidifiers
- Humidifiers
- Water Panels
Dehumidifiers
- Dehumidifiers
- Dehumidifier Filters
Filter Cabinets
Air Purifiers
Parts & Supplies
All Products

Twitter
Facebook
Pinterest
YouTube

Search

Cart

Furnace Filters
Humidifiers
- Humidifiers
- Water Panels
Dehumidifiers
- Dehumidifiers
- Dehumidifier Filters
Filter Cabinets
Air Purifiers
Parts & Supplies
All Products

Save even more when you choose auto- delivery

Learn More

Sort by:

3 of 661 products

Filter:

Nominal Size: 21x26x4 Remove filter

Brand (0)

Brand

Lennox (3 products)

Lennox (3 products)

Nominal Size (1)

Nominal Size

Depth (inches) (0)

Depth (inches)

4 (3 products)

4 (3 products)

MERV (0)

MERV

11 (1 product)
16 (2 products)

11 (1 product)
16 (2 products)

Price

The highest price is $2,695.19

$

From

To

Sort by:

Filter and sort Filter

Filter and sort

Filter

3 of 661 products

Brand

Lennox (3 products)

Clear

Nominal Size

Clear

Depth (inches)

4 (3 products)

Clear

MERV

11 (1 products)
16 (2 products)

Clear

Price

The highest price is $2,695.19

$

From

$

To

Clear

Sort by:

Remove all

Nominal Size: 21x26x4 Remove filter

3 of 661 products

Lennox X6669 PCO-20C | 21" x 26" x 4" MERV 16 PureAir Replacement Filter

Lennox X6669 PCO-20C | 21" x 26" x 4" MERV 16 PureAir Replacement Filter

Regular price $164.78 USD

Regular price Sale price $164.78 USD
Unit price per
Lennox X8345 PCO-20C | 21" x 26" x 4" MERV 16 PureAir Upgrade Kit with Insert

Lennox X8345 PCO-20C | 21" x 26" x 4" MERV 16 PureAir Upgrade Kit with Insert

1 total reviews

Regular price $441.74 USD

Regular price Sale price $441.74 USD
Unit price per
Lennox X8348 PCO-20C | 21" x 26" x 4" MERV 11 PureAir Healthy Climate MAINT KIT W/ INSRT

Lennox X8348 PCO-20C | 21" x 26" x 4" MERV 11 PureAir Healthy Climate MAINT KIT W/ INSRT

Regular price $335.55 USD

Regular price Sale price $335.55 USD
Unit price per

Collection: Products

Your trusted source for air filters, whole-house humidifiers, dehumidifiers and more.

Subscribe To Our Healthy Home eNewsletter & Save 5%!

Email

DiscountFurnaceFilter

At DiscountFurnaceFilter.com, we put customers first by offering genuine OEM products, fast and free shipping, and a commitment to 100% customer satisfaction.

About Us

Our Story
Meet the Team
Transforming Lives
Press & Media
Why Shop With Us?
Trusted & Secure
Customer Testimonials

Customer Service

Contact Us
Account Log In / Register
Shipping & Returns
Privacy Policy
Terms & Conditions
Our Customer Promise

Get Social

Payment methods

Choosing a selection results in a full page refresh.
Opens in a new window.