{"product_id":"carrier-upflow100u4819a-transformer-h3hvc4","title":"OEM Carrier Transformer 120V–24V 40VA for UPFLOW100U4819A","description":"\u003ch1\u003eOEM Carrier Control Transformer 120V to 24V 40VA — HT01CN001 for Model UPFLOW100U4819A\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement control transformer for the \u003cstrong\u003eCarrier UPFLOW100U4819A\u003c\/strong\u003e upflow gas furnace. The transformer steps down 120V line voltage to the 24V used by the low-voltage control circuit — powering the thermostat, control board signals, and every safety relay in the system. When it fails, the entire control circuit goes dark: the thermostat loses power, the furnace will not respond to a call for heat, and no fault codes will appear because the board itself has no power. Replacing this transformer is often the fastest and most cost-effective fix when the system is completely unresponsive.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 120V primary | 12\/24V secondary | 40VA rated | Factory OEM part number HT01CN001 | Direct drop-in replacement for Carrier UPFLOW100U4819A\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound to exact VA and voltage tolerances required by the Carrier control board. Undersized or off-tolerance aftermarket units can cause nuisance tripping, board damage, or unsafe operation — always match factory specs on a control transformer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Turn off all power at the disconnect and breaker before proceeding. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 0V before touching terminals). Label all wiring before disconnecting. Confirm 24V output with a meter before reassembly.\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 specifically for the \u003cstrong\u003eCarrier UPFLOW100U4819A\u003c\/strong\u003e upflow furnace. Verify your existing transformer reads 120V primary and 24V\/40VA secondary on the data plate or unit wiring diagram before ordering. Cross-references include legacy Carrier part numbers HT01BJ115, 19EA41612, and 19EA42612. Our fitment team is available to verify compatibility before you order — don't hesitate to reach out.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62640239313267,"sku":"CARRIE-UPFLOW100U4819A-TRANSFORMER-HT01CN001","price":353.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62640239346035,"sku":"CARRIE-UPFLOW100U4819A-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_ca500417-85ec-4326-911e-4070e67ab318.jpg?v=1775041105","url":"https:\/\/nationalhvacparts.com\/products\/carrier-upflow100u4819a-transformer-h3hvc4","provider":"National HVAC Parts","version":"1.0","type":"link"}