{"product_id":"carrier-c4850c48zg055200-transformer-h302a1","title":"OEM Carrier Transformer 40VA 120V\/24V for C4850C48ZG055200","description":"\u003ch1\u003eOEM Carrier Control Transformer 40VA 120V to 24V for Model C4850C48ZG055200\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement control transformer (part number \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier C4850C48ZG055200\u003c\/strong\u003e packaged unit. The transformer steps down line voltage from 120V to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this transformer fails, the result is total system non-response: the thermostat goes blank, no calls for heating or cooling are answered, and no error codes are generated because the control circuit has no power. A failed transformer is often misdiagnosed as a bad thermostat or control board, making it the first component to test in a completely non-responsive unit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | Primary voltage: 120V | Secondary voltage: 24V | OEM part number HT01BD236 | Carrier-matched output tolerance for stable control circuit operation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM transformer is wound to Carrier's exact VA and voltage specifications. Generic transformers often run under-rated VA loads, causing premature overheating, blown fuses, and repeat failures — especially in multi-stage systems with higher 24V current draw.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, wire nuts. Label all low-voltage wiring before disconnecting. Test secondary output voltage (should read 24–28V AC) after installation to confirm proper operation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed as a direct OEM replacement for \u003cstrong\u003eCarrier model C4850C48ZG055200\u003c\/strong\u003e packaged units. Verify your existing transformer's VA rating and primary\/secondary voltages against your unit's data plate before ordering. Not sure if this part fits your unit? Our HVAC parts specialists verify fitment — contact us before you order. \u003cstrong\u003eIn stock and ships today.\u003c\/strong\u003e\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909864182131,"sku":"CARRIE-C4850C48ZG055200-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909864214899,"sku":"CARRIE-C4850C48ZG055200-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_c7bf7d11-bbda-4d76-bc29-61166eeb1000.jpg?v=1782940100","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c48zg055200-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}