{"product_id":"oem-goodman-flowrator-piston-kit-for-ash130421ac-b1789882","title":"OEM Goodman Flowrator Piston Kit for ASH130421AC — B1789882","description":"\u003cp\u003eThe \u003cstrong\u003eGoodman B1789882 Flowrator Piston Kit\u003c\/strong\u003e is the OEM refrigerant metering device engineered for the \u003cstrong\u003eASH130421AC\u003c\/strong\u003e 13 SEER heat pump condensing unit. This precision-machined restrictor piston (flowrator) controls refrigerant flow into the coil, ensuring correct superheat, subcooling, and rated cooling\/heating capacity. Using the factory-spec orifice is critical — an incorrectly sized piston causes flooding, starving, poor efficiency, and premature compressor wear.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Part Number:\u003c\/strong\u003e B1789882\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Flowrator \/ restrictor piston kit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunction:\u003c\/strong\u003e Fixed-orifice refrigerant metering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e Goodman ASH130421AC heat pump (verify against your unit's parts list)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Brass-body OEM assembly\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOEM vs. Generic\u003c\/h3\u003e\u003cp\u003eThis is the \u003cstrong\u003egenuine Goodman OEM piston\u003c\/strong\u003e, factory-calibrated to the exact bore diameter your system was designed around. Aftermarket universal piston assortments require you to identify and swap the correct orifice yourself — a common source of installer error. Choosing OEM removes the guesswork and protects your compressor warranty.\u003c\/p\u003e\u003ch3\u003eInstallation Difficulty\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eModerate — HVAC technician recommended.\u003c\/strong\u003e Replacement requires recovering the refrigerant charge, opening the sealed system, brazing\/flare access at the metering device, evacuation, and a full recharge to nameplate. EPA 608 certification is required to handle refrigerant. Not a DIY job for homeowners.\u003c\/p\u003e","brand":"Goodman","offers":[{"title":"Default Title","offer_id":63058302534003,"sku":"GOODMAN-16060","price":5.95,"currency_code":"USD","in_stock":true}],"url":"https:\/\/nationalhvacparts.com\/products\/oem-goodman-flowrator-piston-kit-for-ash130421ac-b1789882","provider":"National HVAC Parts","version":"1.0","type":"link"}