{"product_id":"carrier-fc4dnf018010aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120\/24V for FC4DNF018010AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V\/24V for Model FC4DNF018010AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM replacement transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) is the factory-specified step-down transformer for the \u003cstrong\u003eCarrier FC4DNF018010AAAA\u003c\/strong\u003e fan coil unit. Its job is to convert 120V line voltage down to the 24V signal that powers your thermostat, control board, and all low-voltage switching components. When this transformer fails, the entire control circuit goes dark — your thermostat goes blank, the system produces no response to any call for heating or cooling, and nothing turns on. A failed transformer is often misdiagnosed as a control board failure, making correct identification critical before replacing more expensive components.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Input: 120V AC | Output: 24V AC | OEM Part Number: HT01CN241 | Factory-matched electrical tolerances for reliable low-voltage control\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is the genuine OEM Carrier transformer, wound and rated to exact factory specifications. Generic transformers often use undersized VA ratings that can overheat under full control-circuit load, leading to premature failure and potential blown fuses.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Difficulty: 2\/5\u003c\/strong\u003e — Shut off all power to the unit at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 0V before touching wiring). Photograph all wiring connections before disconnecting. The transformer mounts inside the air handler cabinet and connects to both the line-voltage side and the low-voltage control wiring harness.\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 cutoff.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the Carrier \u003cstrong\u003eFC4DNF018010AAAA\u003c\/strong\u003e fan coil unit. Always verify your existing transformer's VA rating and primary\/secondary voltages on the data plate or wiring diagram before ordering. If you're unsure of fitment, our HVAC parts specialists can confirm compatibility before you purchase — same-day shipping available on all in-stock OEM parts.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909523558771,"sku":"CARRIE-FC4DNF018010AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909523591539,"sku":"CARRIE-FC4DNF018010AAAA-TRANSFORMER-HT01CN241-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-HT01CN241_29282f00-01cc-4693-83d4-ae42e09a5667.jpg?v=1782938648","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fc4dnf018010aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}