{"product_id":"carrier-c48a704064-transformer-h301d7","title":"OEM Carrier Transformer 40VA 120V\/24V for C48A704064 — HT01BD702","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer HT01BD702 for Model C48A704064\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement control transformer (part number \u003cstrong\u003eHT01BD702\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier C48A704064\u003c\/strong\u003e packaged unit. The transformer steps down line voltage (120V primary) to the 24V secondary signal used by the thermostat, contactor coil, and all low-voltage control circuits. When this transformer fails, the entire control circuit loses power — the thermostat goes blank, the system won't respond to any calls for heating or cooling, and nothing works. It is one of the most overlooked root causes of a completely unresponsive unit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | 120V primary \/ 24V secondary | Factory OEM part number HT01BD702 | Mounts directly to original bracket without modification\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM transformer is wound to exact factory VA and voltage tolerances. Undersized or off-tolerance generic transformers can overheat under normal control circuit load, trip thermal protectors, and fail prematurely — leaving you with the same no-power symptom within a season.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 24V output after installation). Label all low-voltage wires before disconnecting. Check for a shorted low-voltage circuit if the original transformer failed — replacing the transformer without clearing the short will blow the new unit 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 Designed as the direct OEM replacement for the Carrier \u003cstrong\u003eC48A704064\u003c\/strong\u003e packaged unit. Verify your existing transformer's VA rating and primary\/secondary voltages against your unit's data plate before ordering. Our parts specialists are available to confirm fitment — order with confidence.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909721805171,"sku":"CARRIE-C48A704064-TRANSFORMER-HT01BD702","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909721837939,"sku":"CARRIE-C48A704064-TRANSFORMER-HT01BD702-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-HT01BD702_9f8c253e-0570-434f-b64c-674c316d708a.jpg?v=1782940273","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c48a704064-transformer-h301d7","provider":"National HVAC Parts","version":"1.0","type":"link"}