{"product_id":"carrier-fb4bnf048010aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V-24V for FB4BNF048010AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V\/24V for Model FB4BNF048010AAAA\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier FB4BNF048010AAAA\u003c\/strong\u003e fan coil air handler. The transformer steps down line voltage from 120V to the 24V AC signal that powers your thermostat, control board, and all low-voltage system controls. When this component fails, the entire control circuit goes dead — your thermostat goes blank, the system will not respond to any commands, and nothing operates. If you have 120V at the primary but no 24V at the secondary, this transformer is almost certainly the cause.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | 120V primary \/ 24V secondary | Factory-matched OEM part number HT01CN241 | Designed for Carrier fan coil air handler applications\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is a genuine Carrier OEM transformer built to exact VA and voltage tolerance specifications. Generic alternatives may be under-rated for VA load, causing premature failure or nuisance tripping of the secondary fuse — especially in multi-stage or zoned systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off all power to the air handler before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, wire nuts. Label or photograph all low-voltage wiring connections before disconnecting the old transformer. Confirm 120V supply before replacing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. In-stock orders ship the same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the \u003cstrong\u003eCarrier FB4BNF048010AAAA\u003c\/strong\u003e fan coil air handler. Verify your existing transformer's VA rating and primary\/secondary voltage on the unit data plate or wiring diagram before ordering. Need help confirming fitment? Our HVAC parts specialists are ready to verify compatibility before you buy — same-day shipping available on all in-stock orders.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909540008307,"sku":"CARRIE-FB4BNF048010AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909540041075,"sku":"CARRIE-FB4BNF048010AAAA-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_d8dd7e30-4b0f-43e3-8baa-daba8726394b.jpg?v=1782939501","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fb4bnf048010aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}