{"product_id":"payne-pa12na04800gadaa-pressure-switch-jria74","title":"OEM Payne Pressure Switch HK02ZA395 \/ HK02ZB028 — PA12NA04800GADAA","description":"\u003ch1\u003eOEM Payne High \u0026amp; Low Pressure Switch for Model PA12NA04800GADAA\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 PA12NA04800GADAA\u003c\/strong\u003e heat pump system. Pressure switches monitor refrigerant-side pressures to protect the compressor and system components from operating outside safe limits. When either switch fails, the system will typically lock out before or during operation, displaying a fault code and refusing to run heating or cooling cycles until the fault is cleared.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e HK02ZA395 — High-side pressure switch, factory-calibrated cut-out point | HK02ZB028 — Low-side pressure switch, factory-calibrated cut-in point | Both rated for R-410A refrigerant systems | OEM tolerance-matched for precise pressure sensing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM pressure switches use factory-calibrated setpoints specific to Payne equipment. Generic switches frequently drift outside acceptable pressure thresholds, risking compressor damage, nuisance lockouts, or failure to protect the system during a true refrigerant fault.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 3\/5\u003c\/strong\u003e — Refrigerant system pressure switches require care near the refrigerant circuit. Tools needed: manifold gauge set, adjustable wrench, multimeter, leak-check solution. It is recommended to have an EPA 608-certified technician perform this repair. Always de-energize the unit and verify pressures before disconnecting any switch.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty on both HK02ZA395 and HK02ZB028. Ships same business day from our warehouse when ordered before 3 PM local time.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered specifically for the \u003cstrong\u003ePayne PA12NA04800GADAA\u003c\/strong\u003e 4-ton R-410A heat pump system. Verify your existing switch part numbers against HK02ZA395 and HK02ZB028 on your unit's wiring diagram or data plate before ordering. Not sure which switch you need? Our HVAC parts specialists confirm fitment before every order — call or chat today and ship the right part the same day.\u003c\/p\u003e","brand":"Payne","offers":[{"title":"OEM","offer_id":62909179822451,"sku":"PAYNE-PA12NA04800GADAA-PRESSURE_SWITCH-HK02ZA395","price":43.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909179855219,"sku":"PAYNE-PA12NA04800GADAA-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_d353b9df-1425-4646-bdbb-4a2e769e212e.jpg?v=1780718546","url":"https:\/\/nationalhvacparts.com\/products\/payne-pa12na04800gadaa-pressure-switch-jria74","provider":"National HVAC Parts","version":"1.0","type":"link"}