{"product_id":"carrier-fb4bnf036005aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V\/24V for FB4BNF036005AAAA","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer HT01CN241 for Model FB4BNF036005AAAA\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 FB4BNF036005AAAA\u003c\/strong\u003e fan coil air handler. Its sole but critical job is stepping line voltage (120V) down to the 24V signal voltage that powers your thermostat, contactor coil, and every low-voltage control on the system. When this transformer fails, absolutely nothing responds — the thermostat goes dark, the system refuses to start, and a multimeter will show zero volts on the secondary terminals. If your unit is completely dead and you've already ruled out a tripped breaker, this transformer is almost always the culprit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | Primary: 120V | Secondary: 24V | Factory-matched OEM part number HT01CN241 | Replaces original equipment exactly\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers from Carrier meet exact VA load ratings and insulation class requirements. Undersized or off-spec generic units can overheat, blow the internal fuse, or fail to hold voltage under full control circuit load — returning you to the same no-power symptom within weeks.\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, needle-nose pliers. Note wire colors or photograph existing connections before disconnecting. The secondary fuse (typically 3A) should also be inspected and replaced if blown.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. Orders placed before cutoff ship same business day from our stocked warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered specifically for the Carrier \u003cstrong\u003eFB4BNF036005AAAA\u003c\/strong\u003e fan coil air handler. Verify your existing transformer's primary\/secondary voltage and VA rating on the data plate before ordering to confirm fitment. Our HVAC parts specialists are available to verify compatibility before you buy — call or chat today. In stock and ready to ship.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909540729203,"sku":"CARRIE-FB4BNF036005AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909540761971,"sku":"CARRIE-FB4BNF036005AAAA-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_d80583ee-d830-4095-9e61-5290c712e3c0.jpg?v=1782940899","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fb4bnf036005aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}