{"product_id":"carrier-fc4cnb042000aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V-24V for FC4CNB042000AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V to 24V for Model FC4CNB042000AAAA\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier FC4CNB042000AAAA\u003c\/strong\u003e fan coil unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, and all low-voltage components. When this transformer fails, nothing in the control circuit responds — the thermostat goes blank, the system won't call for heating or cooling, and the unit appears completely dead. It is one of the most commonly overlooked causes of a no-response HVAC system.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e Input: 120V AC | Output: 24V AC | VA Rating: 40VA | OEM Part Number: HT01CN241 | Factory-matched to Carrier FC4CNB042000AAAA wiring harness and control board\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM transformer is wound to exact factory VA and voltage specifications. Generic replacements often deliver inconsistent output voltage under load, causing nuisance lockouts, erratic thermostat behavior, 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. Photograph all wiring connections before removal. Verify primary and secondary voltages with a meter before closing the unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. 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 specifically for the Carrier \u003cstrong\u003eFC4CNB042000AAAA\u003c\/strong\u003e fan coil unit. Confirm your existing transformer's input\/output voltage and VA rating on the data plate before ordering to ensure a correct match. Have questions about fitment? Our HVAC parts specialists verify compatibility before you buy — same-day shipping on all in-stock orders.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909525852531,"sku":"CARRIE-FC4CNB042000AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909525885299,"sku":"CARRIE-FC4CNB042000AAAA-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_63960e20-e625-47a6-847b-d60ecfd28ae4.jpg?v=1782939555","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fc4cnb042000aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}