{"product_id":"oem-goodman-flow-check-piston-kit-for-wghp4360aaa-b1789888","title":"OEM Goodman Flow Check Piston Kit for WGHP4360AAA — B1789888","description":"\u003cp\u003eThe genuine Goodman B1789888 Flow Check Piston Kit is a factory-original metering device made for the Goodman WGHP4360AAA heat pump. The flow-check piston meters refrigerant into the coil in one direction and allows full flow in the other — essential for proper heat-pump operation in both heating and cooling modes. A correctly sized piston is critical to system capacity and efficiency.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOEM Part Number: B1789888\u003c\/li\u003e\n\u003cli\u003eBrand: Goodman\u003c\/li\u003e\n\u003cli\u003eComponent Type: Flow Check Piston \/ Metering Orifice Kit\u003c\/li\u003e\n\u003cli\u003eDesigned Fit: WGHP4360AAA heat pump\u003c\/li\u003e\n\u003cli\u003eFunction: Bi-directional refrigerant metering\u003c\/li\u003e\n\u003cli\u003eCondition: Brand-new OEM\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOEM vs. Generic\u003c\/h3\u003e\u003cp\u003eThis OEM kit is bored to the exact orifice size specified for your unit's tonnage, ensuring proper superheat\/subcooling and rated capacity. Installing the wrong-size generic piston causes poor cooling, high head pressure, or compressor strain. Because the bore size is matched to the system, the OEM part removes the guesswork.\u003c\/p\u003e\u003ch3\u003eInstallation Difficulty\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eAdvanced — Professional Only\u003c\/strong\u003e — Installation requires refrigerant recovery, opening the liquid-line fitting to swap the piston and O-ring\/seal, re-sealing, evacuating, and recharging. This is EPA Section 608 work and should be handled by a certified HVAC technician.\u003c\/p\u003e","brand":"Goodman","offers":[{"title":"Direct Replacement","offer_id":63032347165043,"sku":"B1789888-GEN","price":5.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048238760307,"sku":"B1789888","price":7.74,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-piston-B1789888_952bc949-5118-4ac0-ab62-27093074ab47.jpg?v=1782948282","url":"https:\/\/nationalhvacparts.com\/products\/oem-goodman-flow-check-piston-kit-for-wghp4360aaa-b1789888","provider":"National HVAC Parts","version":"1.0","type":"link"}