{"product_id":"hayward-manual-air-relief-valve-assembly-dex2420mar2-for-de-cartridge-vertical-grid-filters-restores-venting-prevents-air-loc","title":"Hayward manual air relief valve assembly DEX2420MAR2 for DE \u0026 cartridge vertical-grid filters — restores venting, prevents air loc","description":"\u003cp\u003e\u003cstrong\u003eHayward DEX2420MAR2 is a manual air-relief valve assembly designed to release trapped air from Hayward vertical grid-style DE and cartridge pool filters.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis compact replacement part restores safe, effective venting for Hayward Pro-Grid DE, SwimClear and Swimclear cartridge filters, helping the filtration system run efficiently by letting air escape before normal operation. Built in the United States, the assembly is a straightforward service component for pool owners and technicians maintaining compatible Hayward vertical filters. Some installations may also require the DEX2420Z8A O-ring kit (two O-rings) to ensure a leak-free seal.\u003c\/p\u003e\n\n\u003ch3\u003eHow do I know this assembly fits my Hayward filter?\u003c\/h3\u003e\n\u003cp\u003eConfirm fit by matching your filter model to the compatible list: Pro-Grid DE models and SwimClear\/Swimclear cartridge filters that use the vertical grid-style top vent. Check the filter top for existing manual relief hardware geometry and thread style.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible with Hayward Pro-Grid DE filters.\u003c\/li\u003e\n  \u003cli\u003eWorks on SwimClear and Swimclear cartridge vertical-grid filters.\u003c\/li\u003e\n  \u003cli\u003eCompare threads and valve location to your current relief valve.\u003c\/li\u003e\n  \u003cli\u003eMay need DEX2420Z8A O-ring kit for proper sealing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat does the manual air relief assembly do for pool performance?\u003c\/h3\u003e\n\u003cp\u003eThe valve helps purge trapped air from the filter tank before the pump runs at normal pressure, preventing loss of prime, noisy operation, and pressure spikes. Regularly venting air improves circulation consistency and protects pump and filter components from cavitation and stress.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAllows trapped air to escape safely from the filter head.\u003c\/li\u003e\n  \u003cli\u003eHelps maintain steady pump prime and flow rate.\u003c\/li\u003e\n  \u003cli\u003eReduces noise and pressure fluctuations during start-up.\u003c\/li\u003e\n  \u003cli\u003eExtends life of filter grids and pump by preventing cavitation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat installation or replacement steps should I follow?\u003c\/h3\u003e\n\u003cp\u003eInstallation is typically straightforward: turn off the pump, relieve tank pressure, remove the old valve, inspect the mounting surface and threads, fit the new assembly, and test for leaks. Use a compatible O-ring if the original is worn or missing for a reliable seal.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eShut off pump and open filter drain to relieve pressure.\u003c\/li\u003e\n  \u003cli\u003eRemove the old relief valve and clean mating surfaces.\u003c\/li\u003e\n  \u003cli\u003eInstall new DEX2420MAR2 assembly, replace O-rings if needed.\u003c\/li\u003e\n  \u003cli\u003eRestart system and check for proper venting and leaks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAre replacement parts or accessories required?\u003c\/h3\u003e\n\u003cp\u003eMany swaps are direct replacements, but aging filters often need fresh sealing hardware. The DEX2420Z8A O-ring kit (set of 2) is commonly recommended to ensure a tight fit and prevent leaks; check your valve and filter head for wear before finalizing installation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDEX2420Z8A O-ring kit may be required for a leak-free fit.\u003c\/li\u003e\n  \u003cli\u003eInspect existing threads and gasket surfaces for damage.\u003c\/li\u003e\n  \u003cli\u003eUse compatible lubricants sparingly on O-rings if installing new seals.\u003c\/li\u003e\n  \u003cli\u003eKeep manufacturer instructions and part numbers on hand during maintenance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: pool owners, maintenance technicians, and service shops that use Hayward vertical grid-style filters and need a reliable manual air-relief solution. If you maintain Pro-Grid DE or SwimClear cartridge systems and want a direct-fit replacement made in the United States, the DEX2420MAR2 provides a durable option to restore proper venting. For older filters, have the DEX2420Z8A O-ring kit available to complete the repair and ensure a leak-tight seal.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will this fit my Hayward Pro-Grid DE filter?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — the DEX2420MAR2 is designed to fit Hayward Pro-Grid DE vertical grid-style filters; verify thread and valve location before installing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Do I need extra parts to install it?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Possibly — many installs require the DEX2420Z8A O-ring kit (set of 2) to ensure a proper seal and prevent leaks.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Hayward","offers":[{"title":"Default Title","offer_id":56805981585748,"sku":"B0032UXRJQ","price":201.19,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1063\/2652\/4244\/files\/hayward-dex2420mar2-assembly-front.jpg?v=1786811004","url":"https:\/\/gardenluxe.co.uk\/products\/hayward-manual-air-relief-valve-assembly-dex2420mar2-for-de-cartridge-vertical-grid-filters-restores-venting-prevents-air-loc","provider":"Gardenluxe Uk","version":"1.0","type":"link"}