WaterFurnace Geothermal 24x28x1 MERV 10 Airguard Air Filter - 4 Pack

The WaterFurnace 2428WF is the OEM replacement 1" pre-filter manufactured by Airguard for WaterFurnace Geothermal Systems. It is the factory-recommended 24" × 28" × 1" MERV 10 filter for units that require a full-size 1" pre-filter.

Update: The MERV 11 version has been discontinued. WaterFurnace now supplies this MERV 10 model to meet airflow and efficiency requirements.

Why Full-Size Filters Matter

This genuine 2428WF is a true 24" × 28" filter for a proper seal that helps prevent air bypass (unfiltered air leaking around undersized filters).

Compatible Systems

Common WaterFurnace geothermal heat pump models using the 24×28×1 pre-filter include:

• 6 Series Vertical Units: 022, 026, 030

Filter Media & Performance

Constructed of 100% synthetic, needled fibers that are electrostatically charged to capture particles efficiently while maintaining low airflow resistance and system performance.

Replacement Interval

Replace every 4–6 months, depending on operating conditions and household environment. Refer to your unit’s Owner’s Manual for installation and maintenance.

What’s Included

Quantity: 4 filters per package.

Specifications

Note: Always verify sizing and replacement procedures in your WaterFurnace Owner’s Manual.