{"product_id":"pentair-fns-plus-tank-48-sf-170021","title":"Pentair Tank Lid, 48 sq. ft. Filter | FNS Plus | 170021","description":"\u003cp\u003eThe 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.\u003c\/p\u003e\n\n\u003cp\u003eThe 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.\u003c\/p\u003e\n\n\u003cp style=\"background-color: #fff3cd; border: 2px solid #FFEAA7; padding: 15px; border-radius: 5px; margin: 15px 0; color: #856404;\"\u003e\u003cstrong\u003eIMPORTANT: CONFIRM YOUR FILTER MODEL BEFORE ORDERING\u003c\/strong\u003e\u003cbr\u003eThis 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.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; margin: 20px 0; border: 1px solid #ccc;\"\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePentair Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e170021\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePart Name\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eTank Lid, 48 sq. ft. Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePart Category\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eTank Lids\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eQuantity Included\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e1 (Each)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eCompatible Filter Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e48 sq ft\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eFits Into\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; margin: 20px 0; border: 1px solid #ccc;\"\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eEquipment Line\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eModel \/ Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eNotes\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003ePentair\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eFNS Plus\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eFNS PLUS 48\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eTank lid, 48 sq. ft. filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eCompatibility 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.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003ePoolaroo Pro Tip\u003c\/h3\u003e\n\u003cp\u003eWhen 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.\u003c\/p\u003e\n\n\u003c!-- wft:processed:manual:2026-04-30 --\u003e","brand":"Pentair","offers":[{"title":"Default Title","offer_id":51774120624403,"sku":"170021","price":374.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0920\/0687\/5411\/files\/PEN170021_0.jpg?v=1747699452","url":"https:\/\/poolaroo.com\/products\/pentair-fns-plus-tank-48-sf-170021","provider":"Poolaroo","version":"1.0","type":"link"}