{"product_id":"carrier-c4850c48ay04161-transformer-h302a1","title":"OEM Carrier Transformer 40VA 120V\/24V for C4850C48AY04161","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer for Model C4850C48AY04161\u003c\/h1\u003e\u003cp\u003eThis OEM step-down transformer (part# \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eCarrier C4850C48AY04161\u003c\/strong\u003e packaged unit. The transformer converts 120V line voltage down to the 24V signal required by your thermostat, control board, contactor coil, and all low-voltage control circuits. When it fails, the entire control circuit goes dead — your thermostat goes blank, the system won't respond to any call for heating or cooling, and nothing happens when you cycle the unit. A failed transformer is often misdiagnosed as a bad control board, making this a critical first diagnostic step.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | 120V primary \/ 24V secondary | Class 2 current-limited | OEM part number HT01BD236 | Factory-matched output tolerance for reliable low-voltage control\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM transformer is wound and insulated to Carrier's exact factory specification. Generic transformers frequently under-deliver rated VA, causing nuisance tripping of the internal thermal fuse and erratic control board behavior — especially under high contactor coil demand.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire nuts or terminal connectors, multimeter to confirm 24V output after installation. Label all wires before disconnecting the old unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse when ordered before 3PM local time.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered specifically for the \u003cstrong\u003eCarrier C4850C48AY04161\u003c\/strong\u003e packaged unit. Always verify your existing transformer's VA rating and primary\/secondary voltages on the unit data plate or wiring diagram before ordering. If your system is tripping the transformer repeatedly, inspect for shorted low-voltage wiring before replacing — a wiring short will take out a new transformer just as fast. Our parts team is available to confirm fitment before you order. \u003cstrong\u003eOrder now and receive same-day shipping!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909877682547,"sku":"CARRIE-C4850C48AY04161-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909877715315,"sku":"CARRIE-C4850C48AY04161-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_8eaff899-f98f-4a2c-a386-02433a20fae2.jpg?v=1782940060","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c48ay04161-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}