{"product_id":"carrier-upflow100u4219a-transformer-h3hvc4","title":"OEM Carrier Transformer 120V–24V 40VA for UPFLOW100U4219A","description":"\u003ch1\u003eOEM Carrier Furnace Transformer 120V to 24V 40VA — Model UPFLOW100U4219A\u003c\/h1\u003e\u003cp\u003eThis is the genuine OEM Carrier transformer (part number \u003cstrong\u003eHT01CN001\u003c\/strong\u003e), factory-specified for the \u003cstrong\u003eUPFLOW100U4219A\u003c\/strong\u003e upflow furnace. The transformer steps down 120V line voltage to a safe 24V (with 12V secondary tap) to power all low-voltage control circuits — including the thermostat, control board relay coils, and zone valves. At 40VA, it delivers sufficient capacity for multi-stage systems. When this transformer fails, the entire control circuit loses power: the thermostat goes blank, the furnace will not respond to any call for heat, and diagnostics cannot run. Common causes of failure include voltage surges, short circuits in low-voltage wiring, and age-related winding breakdown.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 120V primary | 24V \/ 12V secondary | 40VA rated | Factory-matched Carrier OEM replacement | Replaces legacy part numbers HT01BJ115, 19EA41612, 19EA42612\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e The OEM HT01CN001 is wound to exact Carrier factory tolerances, ensuring stable 24V output under full load. Generic aftermarket transformers may under-deliver on VA capacity, causing nuisance brownouts and premature control board failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Difficulty: 2\/5\u003c\/strong\u003e — Shut off power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, multimeter (to confirm 24VAC output after install), wire stripper\/connectors if needed. Label all low-voltage wires before disconnecting. Confirm no short circuits in the 24V wiring loop before energizing, or the new transformer may fail 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 as a direct OEM replacement for the Carrier \u003cstrong\u003eUPFLOW100U4219A\u003c\/strong\u003e upflow furnace. Verify part number and voltage rating on your unit's data label before ordering. Our technical team is available to confirm fitment — contact us before you buy if you have any questions. Order today and get same-day shipping on in-stock parts.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62640239903091,"sku":"CARRIE-UPFLOW100U4219A-TRANSFORMER-HT01CN001","price":353.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62640239935859,"sku":"CARRIE-UPFLOW100U4219A-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_0d5be451-d300-4750-9b26-a64dfc14d122.jpg?v=1775041103","url":"https:\/\/nationalhvacparts.com\/products\/carrier-upflow100u4219a-transformer-h3hvc4","provider":"National HVAC Parts","version":"1.0","type":"link"}