{"product_id":"carrier-fb4bnf030015aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V\/24V for FB4BNF030015AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V\/24V for Model FB4BNF030015AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM control circuit transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eCarrier FB4BNF030015AAAA\u003c\/strong\u003e fan coil air handler. The transformer steps down line voltage from 120V to 24V AC to power the low-voltage control circuit — including the thermostat, control board, and all relay coils. When this transformer fails, the entire control system goes dark: the thermostat loses power, the system refuses to respond to any call for heating or cooling, and nothing turns on. If your system is completely unresponsive and your low-voltage fuse keeps blowing, a failed transformer is the most likely culprit.\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 output for stable control voltage under full load\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound and insulated to Carrier's exact specifications, ensuring consistent 24V output even under peak load from multiple relay coils. Generic units can sag under load, causing erratic thermostat behavior or intermittent lockouts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Photograph existing wiring before disconnecting. Check and replace any blown low-voltage fuse before installing the new transformer to avoid repeat failures.\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 specifically for the Carrier \u003cstrong\u003eFB4BNF030015AAAA\u003c\/strong\u003e fan coil air handler. Verify your existing transformer's VA rating and primary\/secondary voltages on the unit data plate before ordering. Our team is available to confirm fitment — order with confidence.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909540991347,"sku":"CARRIE-FB4BNF030015AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909541024115,"sku":"CARRIE-FB4BNF030015AAAA-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_476e43a4-2998-4df0-aaa2-0e4ab3d3cdcf.jpg?v=1782940897","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fb4bnf030015aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}