Pentair Tank Lid, 48 sq. ft. Filter | FNS Plus | 170021

The Pentair Tank Lid, 48 sq. ft. Filter (170021) is the OEM replacement lid for the FNS Plus 48 sq ft D.E. filter — model FNS PLUS 48. This is a direct factory-matched replacement that restores the pressure-retaining top closure of the filter tank to original specification.

The tank lid forms the sealed top of the FNS Plus filter tank. A cracked, warped, or seal-compromised lid allows system pressure to escape, reducing filtration efficiency and creating a potential safety hazard at the filter head. Replacing with the correct OEM lid restores rated operating integrity and ensures proper seating of the internal D.E. grid assembly.

IMPORTANT: CONFIRM YOUR FILTER MODEL BEFORE ORDERING
This lid is sized specifically for the FNS Plus 48 sq ft model (FNS PLUS 48). Lid assemblies are not interchangeable across FNS Plus tank sizes. Verify your model number on the filter label before ordering.

Specifications

Fits Into

Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment's manual or on the original part itself before ordering.

Poolaroo Pro Tip

When replacing the tank lid, inspect the lid O-ring at the same time. A lid in poor condition often indicates the O-ring has been compressed or damaged — replacing both in the same service visit eliminates a second teardown. Confirm the part number against your existing lid or your filter's parts diagram before ordering; FNS Plus lid assemblies are size-specific and not cross-compatible between tank sizes.