{"product_id":"carrier-c4850c48ay02051-transformer-h302a1","title":"OEM Carrier Transformer 40VA 120V\/24V for C4850C48AY02051","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer for Model C4850C48AY02051\u003c\/h1\u003e\u003cp\u003eThis OEM step-down transformer (part# \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eCarrier C4850C48AY02051\u003c\/strong\u003e packaged unit. The transformer steps down 120V line voltage to the 24V signal required to power the thermostat, control board, contactor coil, and every other low-voltage control circuit in your system. When the transformer fails — due to a shorted wire, failed component, or overload — absolutely nothing responds: no thermostat display, no fan, no heat, no cooling. If you're measuring zero or severely reduced voltage on the 24V secondary side, this transformer is the likely culprit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory-matched impedance and thermal protection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM unit matches the exact VA rating and thermal cutout spec of the original. Undersized or off-spec generic transformers can fail rapidly when control circuit loads spike, or cause nuisance lockouts from voltage sag across the 24V circuit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker before proceeding. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or terminal connectors. Label and photograph all wiring connections before removing the original transformer. Verify no downstream short exists before energizing the replacement — a shorted wire will blow the new transformer immediately.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered and factory-tested for the Carrier \u003cstrong\u003eC4850C48AY02051\u003c\/strong\u003e packaged unit. Always confirm voltage ratings and VA on your unit's data plate before ordering. Our technical team is available to verify fitment — call or chat before you order. Order by 3PM local time for same-day shipping.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909886497139,"sku":"CARRIE-C4850C48AY02051-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909886529907,"sku":"CARRIE-C4850C48AY02051-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_38cccabf-71de-4f29-bad7-e81e9b6965d7.jpg?v=1782940039","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c48ay02051-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}