{"product_id":"carrier-fc4dnf042000aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 24V for FC4DNF042000AAAA — HT01CN241","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer for Model FC4DNF042000AAAA (HT01CN241)\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier FC4DNF042000AAAA\u003c\/strong\u003e air handler. The transformer is the backbone of your system's 24V control circuit — it steps down 120V line voltage to the 24V signal voltage required by your thermostat, control board, contactor coil, and zone valves. When the transformer fails, the entire control circuit goes dead: your thermostat goes blank, the system will not respond to any call for heating or cooling, and no safety lockout codes are generated because the board itself has no power.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | 120V primary \/ 24V secondary | OEM part number HT01CN241 | Factory-matched to Carrier FC4DNF042000AAAA air handler control circuit requirements\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound to exact VA tolerances for this unit. Undersized or generic transformers can overheat, blow internal fuses, or fail to sustain 24V under full relay load — leading to nuisance lockouts and premature control board failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label all wiring connections before removal. Verify 24V output with a multimeter before reinstalling 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 for the Carrier \u003cstrong\u003eFC4DNF042000AAAA\u003c\/strong\u003e fan coil air handler. Always verify your existing transformer's VA rating and primary\/secondary voltages on the unit data plate before ordering to ensure a proper fit. Have questions about fitment? Our HVAC parts specialists confirm compatibility before you buy — no guesswork.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909522608499,"sku":"CARRIE-FC4DNF042000AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909522641267,"sku":"CARRIE-FC4DNF042000AAAA-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_4188fe9c-4677-4980-bcee-c541040ae166.jpg?v=1782942546","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fc4dnf042000aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}