{"product_id":"carrier-c4850c48zn040900-transformer-h302a1","title":"OEM Carrier 40VA 120V to 24V Control Transformer for C4850C48ZN040900 | National HVAC Parts","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer for Model C4850C48ZN040900\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier control transformer (part# \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eC4850C48ZN040900\u003c\/strong\u003e packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, contactor coil, control board, and all low-voltage control circuits. When this component fails, the entire control system goes dark — the thermostat loses power, the unit will not respond to any calls for heating or cooling, and no fault codes will display. It is often the first component to check when a system appears completely unresponsive despite confirmed line voltage at the unit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | 120V primary \/ 24V secondary | OEM part number HT01BD236 | Direct drop-in replacement with factory-matched wiring terminals\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound and insulated to Carrier's exact VA and thermal specifications. Generic alternatives frequently run at marginal VA capacity, causing nuisance tripping, overheating, and premature failure — especially when multiple 24V accessories are on the circuit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, wire stripper, multimeter (to confirm 24V output after install). Label all low-voltage wires before disconnecting from old transformer terminals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our climate-controlled warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered specifically for the Carrier \u003cstrong\u003eC4850C48ZN040900\u003c\/strong\u003e packaged unit. Always verify your existing transformer's VA rating and primary\/secondary voltages on the unit data plate before ordering. Our HVAC parts specialists are available to confirm fitment — order with confidence and get your system back online fast.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909857857907,"sku":"CARRIE-C4850C48ZN040900-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909857890675,"sku":"CARRIE-C4850C48ZN040900-TRANSFORMER-HT01BD236-GEN","price":18.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-HT01BD236_7282e7ae-dabd-4b06-97f0-134290bb4e52.jpg?v=1782899083","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c48zn040900-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}