{"product_id":"payne-pa12na03000gacaa-pressure-switch-jria74","title":"OEM Payne Pressure Switch High\/Low for PA12NA03000GACAA","description":"\u003ch1\u003eOEM Payne High \u0026amp; Low Pressure Switch for Model PA12NA03000GACAA\u003c\/h1\u003e\u003cp\u003eThese OEM pressure switches — \u003cstrong\u003eHK02ZA395 (High Pressure Switch)\u003c\/strong\u003e and \u003cstrong\u003eHK02ZB028 (Low Pressure Switch)\u003c\/strong\u003e — are the factory-specified replacements for the \u003cstrong\u003ePayne PA12NA03000GACAA\u003c\/strong\u003e split-system heat pump. Pressure switches monitor refrigerant-side conditions, protecting the compressor from operating outside safe high- and low-side pressure limits. When either switch fails or sticks open, the control board will lock out the system before or during a heating\/cooling cycle — often with no obvious mechanical noise, making diagnosis tricky without a multimeter or manifold gauge set.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e High pressure switch — OEM# \u003cstrong\u003eHK02ZA395\u003c\/strong\u003e | Low pressure switch — OEM# \u003cstrong\u003eHK02ZB028\u003c\/strong\u003e | Factory-calibrated trip points | SPST normally-closed contacts | Direct OEM replacement — no wiring modifications required\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM switches are calibrated to exact factory cut-out and cut-in pressures for R-410A systems. Generic alternatives often carry wider tolerances that can allow nuisance trips or, worse, fail to protect the compressor at true fault pressures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 3\/5\u003c\/strong\u003e — Refrigerant-side pressure switches require recovering or isolating refrigerant before disconnecting. Tools needed: manifold gauge set, multimeter, 1\/4\" nut driver, needle-nose pliers. Always verify the system is de-energized and pressure is safely relieved before disconnecting switch leads. Photograph all wiring before removal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. Orders placed by 3 PM ship same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered specifically for the \u003cstrong\u003ePayne PA12NA03000GACAA\u003c\/strong\u003e split-system heat pump. Verify your existing switch OEM part number (HK02ZA395 for high side, HK02ZB028 for low side) against your unit's wiring diagram or data plate before ordering. Need help confirming fitment? Our HVAC parts specialists verify compatibility before you buy — just reach out before placing your order.\u003c\/p\u003e","brand":"Payne","offers":[{"title":"OEM","offer_id":62909198401907,"sku":"PAYNE-PA12NA03000GACAA-PRESSURE_SWITCH-HK02ZA395","price":43.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909198434675,"sku":"PAYNE-PA12NA03000GACAA-PRESSURE_SWITCH-HK02ZA395-GEN","price":38.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-pressure-switch-HK02ZA395_1a843b3e-48e3-42ba-a6c2-b899f9d5c1dd.jpg?v=1780718466","url":"https:\/\/nationalhvacparts.com\/products\/payne-pa12na03000gacaa-pressure-switch-jria74","provider":"National HVAC Parts","version":"1.0","type":"link"}