Pentair FNS PLUS Replacement Manifold Top 59023700 — Air-Bleed Port, OEM Fit (16in)

Pentair 59023700 is the replacement manifold top with an integrated air-bleed port designed for FNS PLUS pool and spa D.E. filters.

This replacement manifold top restores proper circulation and simple air release in Pentair FNS PLUS diatomaceous earth filters. Built to the original equipment specifications in the United States, the unit provides a direct-fit solution for worn or damaged tops, helping extend the life of your filter assembly and maintain consistent flow performance. Use it when your existing manifold shows cracks, leaks, or an air-lock that keeps the filter from priming correctly.

How does the Pentair 59023700 improve filter performance?

Replacing a damaged or leaking manifold top with this OEM part ensures the internal laterals and air-bleed feature work as intended, stabilizing water flow and preventing air pockets. The correct fit keeps the D.E. grid assembly aligned and the filter pressurized within its design range.

• Restores factory sealing surfaces for leak-free operation.
• Re-enables the air-bleed port for easier priming and bleeding of trapped air.
• Maintains proper lateral alignment to avoid channeling and flow loss.

Will this part fit my Pentair FNS PLUS filter model?

The 59023700 manifold top is intended specifically for Pentair FNS PLUS pool and spa D.E. filters with matching dimensions. Confirm compatibility by comparing measurements and part numbers; this avoids fitment issues and ensures correct function.

• Matches OEM geometry for Pentair FNS PLUS series filters.
• Dimensions: approximately 16 inches length, 15 inches width, 7-3/4 inches height.
• Manufactured in the United States to original Pentair specifications.

How do I install the replacement manifold top?

Installation is straightforward for a homeowner comfortable with basic pool equipment maintenance. Key steps include draining and opening the filter, removing the old top, inspecting laterals and gaskets, and securing the new manifold with the original clamps or bolts following manufacturer torque guidance.

• Drain the filter and relieve internal pressure before disassembly.
• Inspect DE laterals and diffuser for wear; replace if damaged.
• Use a new gasket and tighten clamps evenly to avoid distortion.

What materials and build quality can I expect from this replacement?

Pentair builds this manifold top to withstand typical pool chemical exposure and pressure cycling. The part is engineered for resilience, matching the original part's dimensions and functional features such as the air-bleed port and manifold seals.

• Durable molded construction compatible with pool chemicals.
• Integrated air-bleed fitting for convenient venting during startup.
• OEM tolerances to ensure reliable long-term operation when installed correctly.

Who this is for: The Pentair 59023700 manifold top is intended for pool owners, service technicians, and maintenance professionals who operate Pentair FNS PLUS D.E. filters and need an exact-fit replacement part. Choose this manifold top if the existing top on your filter is cracked, leaking, or preventing the filter from priming properly, and if you want a direct OEM replacement made to original specifications in the United States.