{"product_id":"carrier-fx4bnf030000aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V\/24V for FX4BNF030000AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V to 24V for Model FX4BNF030000AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM replacement transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) is the factory-specified control circuit transformer for the \u003cstrong\u003eCarrier FX4BNF030000AAAA\u003c\/strong\u003e fan coil air handler. The transformer steps line voltage (120V) down to the 24V low-voltage signal that powers your thermostat, control board, and all relay coils throughout the system. When this component fails, the entire control circuit goes dark — you'll see a blank thermostat, an unresponsive system, or a tripped secondary fuse with no obvious cause. It is one of the first components to test when nothing works at all.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01CN241 | Factory-matched output for stable low-voltage control circuit operation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is the genuine OEM Carrier transformer, wound to exact VA and voltage tolerances. Undersized or off-tolerance generic transformers can overheat, trip the secondary fuse repeatedly, or deliver unstable 24V that causes erratic board behavior and misdiagnosis.\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 screwdriver, multimeter, wire nuts or spade connectors. Always verify 0V at primary terminals before touching wiring. Label all low-voltage leads before removal.\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\u003eFX4BNF030000AAAA\u003c\/strong\u003e fan coil air handler. Confirm your existing transformer's VA rating and primary\/secondary voltages on the unit data plate or wiring diagram before ordering. If you're unsure of fitment, our parts specialists are available to verify compatibility before you purchase — same-day shipping guaranteed on all in-stock orders.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909487448435,"sku":"CARRIE-FX4BNF030000AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909487481203,"sku":"CARRIE-FX4BNF030000AAAA-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_6c251e12-4016-481a-b8ff-e7d0b445ecdd.jpg?v=1782941165","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fx4bnf030000aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}