{"product_id":"carrier-u19x125u48a-transformer-h3hvc4","title":"OEM Carrier Furnace Transformer 40VA 120V\/24V — U19X125U48A","description":"\u003ch1\u003eOEM Carrier Furnace Transformer 40VA 120V to 24V for Model U19X125U48A\u003c\/h1\u003e\u003cp\u003eThe Carrier \u003cstrong\u003eHT01CN001\u003c\/strong\u003e is the factory-specified control circuit transformer for the \u003cstrong\u003eU19X125U48A\u003c\/strong\u003e HVAC unit. It steps down 120V line voltage to a safe 12\/24V output at 40VA — powering the low-voltage control circuit that drives your thermostat, contactor coils, and safety switches. When this transformer fails, the entire control circuit goes dark: the thermostat loses power, the system will not respond to any call for heating or cooling, and you may detect a faint burning smell or buzzing from the transformer housing. Electrical surges and shorted control wiring are the most common causes of failure.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 120V primary | 12\/24V secondary | 40VA rating | Class 2 control transformer | Replaces legacy part numbers HT01BJ115, 19EA41612, and 19EA42612\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is a genuine Carrier OEM part. Factory-wound transformers meet exact VA and impedance specs for the U19X125U48A control board. Undersized or off-spec generic transformers can overheat, trip the fuse, and damage the control board — far costlier than the part itself.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 3\/5\u003c\/strong\u003e — Always disconnect power at the breaker and confirm 0V with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter, wire nuts or quick-disconnects. Photograph all low-voltage wiring before removal. Check for any shorted wire in the 24V circuit before energizing the new transformer or it will fail again.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before the cutoff.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Factory-matched replacement for Carrier model \u003cstrong\u003eU19X125U48A\u003c\/strong\u003e. Always verify the transformer's VA rating and primary\/secondary voltages against your unit's wiring diagram before ordering. Need help confirming fitment? Our HVAC parts specialists verify compatibility before you buy — no guesswork.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62640247308659,"sku":"CARRIE-U19X125U48A-TRANSFORMER-HT01CN001","price":353.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62640247341427,"sku":"CARRIE-U19X125U48A-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_2b95b63f-29ad-42f5-938b-a2f531c53124.jpg?v=1775031843","url":"https:\/\/nationalhvacparts.com\/products\/carrier-u19x125u48a-transformer-h3hvc4","provider":"National HVAC Parts","version":"1.0","type":"link"}