{"product_id":"payne-pa10pa048000adaa-pressure-switch-jria74","title":"OEM Payne Pressure Switch High\/Low for PA10PA048000ADAA","description":"\u003ch1\u003eOEM Payne High \u0026amp; Low Pressure Switch for Model PA10PA048000ADAA\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 PA10PA048000ADAA\u003c\/strong\u003e packaged air conditioning unit. Pressure switches monitor the inducer assembly and refrigerant circuit to verify safe operating conditions before allowing the system to proceed through its startup sequence. When either switch fails or sticks open, the control board interprets the fault as an unsafe condition and locks out the unit — typically before ignition or cooling ever begins. Common symptoms include a system that attempts to start, runs the inducer briefly, and then shuts down with a diagnostic fault code indicating a pressure switch failure.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e HK02ZA395 — High Pressure Switch | HK02ZB028 — Low Pressure Switch | Factory-calibrated W.C. (water column) set points | OEM-matched electrical connectors for direct plug-in replacement | Designed for Payne PA10PA048000ADAA 4-ton packaged unit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM pressure switches are calibrated to exact factory W.C. thresholds. Aftermarket substitutes frequently carry wider tolerances, which can cause nuisance lockouts, missed fault detection, or unsafe operation — especially critical in a packaged rooftop unit where serviceability is limited.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Difficulty: 3\/5\u003c\/strong\u003e — Access requires removing the unit's service panel. Tools needed: 1\/4\" and 5\/16\" nut drivers, needle-nose pliers, multimeter (to verify switch continuity at rest and under pressure), and a manometer if re-verifying set point after installation. Always disconnect power before servicing. Photograph all tubing and wiring connections before removal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects in materials and workmanship. Orders placed by 3 PM local time ship same business day from our climate-controlled parts warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e These switches are engineered specifically for the \u003cstrong\u003ePayne PA10PA048000ADAA\u003c\/strong\u003e 4-ton packaged air conditioner. Confirm the OEM part numbers HK02ZA395 and HK02ZB028 against your unit's data plate or existing switch labeling before ordering. If you need help verifying fitment, our HVAC parts specialists can cross-reference your unit before you buy — call or chat today. In stock and ready to ship.\u003c\/p\u003e","brand":"Payne","offers":[{"title":"OEM","offer_id":62909215703411,"sku":"PAYNE-PA10PA048000ADAA-PRESSURE_SWITCH-HK02ZA395","price":43.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909215736179,"sku":"PAYNE-PA10PA048000ADAA-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_15e45a79-c89b-4db6-9942-6e4c199837f5.jpg?v=1780718455","url":"https:\/\/nationalhvacparts.com\/products\/payne-pa10pa048000adaa-pressure-switch-jria74","provider":"National HVAC Parts","version":"1.0","type":"link"}