{"product_id":"carrier-u19x125u48b-transformer-h3hvc4","title":"OEM Carrier Transformer 120V–24V 40VA for U19X125U48B","description":"\u003ch1\u003eOEM Carrier Furnace Transformer 120V to 24V 40VA — Model U19X125U48B (HT01CN001)\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer for the \u003cstrong\u003eCarrier U19X125U48B\u003c\/strong\u003e HVAC system. The transformer steps down 120V line voltage to a safe 24V (with 12V tap) to power all low-voltage control circuits — including your thermostat, contactor coil, control board, and zone valves. When the transformer fails, the entire control circuit goes dark: the thermostat loses power, the system refuses to start on any call for heating or cooling, and you may notice a faint burning smell or audible buzzing from the transformer itself.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 120V primary | 24V \/ 12V dual secondary | 40VA rated | Factory-matched OEM part number HT01CN001 | Replaces legacy part numbers HT01BJ115, 19EA41612, 19EA42612\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Generic transformers can run under-rated VA, causing premature overload failure, nuisance tripping of the internal fuse, or erratic thermostat behavior — especially on systems with multiple zones or communicating controls.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 3\/5\u003c\/strong\u003e — Turn off all power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter, wire nuts or terminal screws. Label all low-voltage wires (R, C, G, W, Y) before disconnecting. Verify 24V output with a multimeter before reassembling the panel.\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 a direct drop-in replacement for the Carrier \u003cstrong\u003eU19X125U48B\u003c\/strong\u003e unit. Verify your unit's data plate shows a 120V primary \/ 24V secondary control circuit and 40VA rating before ordering. Cross-references include HT01CN001A and Standex Electronics FT3746. Questions about fitment? Our HVAC parts specialists verify compatibility before you order — call or chat today.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62640247046515,"sku":"CARRIE-U19X125U48B-TRANSFORMER-HT01CN001","price":353.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62640247079283,"sku":"CARRIE-U19X125U48B-TRANSFORMER-HT01CN001-GEN","price":311.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-HT01CN001_2d8e3881-55d4-4d06-bb13-6e134aed0991.jpg?v=1775041093","url":"https:\/\/nationalhvacparts.com\/products\/carrier-u19x125u48b-transformer-h3hvc4","provider":"National HVAC Parts","version":"1.0","type":"link"}