{"product_id":"carrier-fx4bnf042000aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V–24V for FX4BNF042000AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V–24V for Model FX4BNF042000AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier control transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eFX4BNF042000AAAA\u003c\/strong\u003e air handler. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage switching circuits. When this component fails, the entire control circuit goes dead — your thermostat displays nothing or fails to call, and the system will not respond to any commands. If you've already confirmed your thermostat and control board are functional, a failed transformer is the most common remaining culprit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched output tolerance | Compatible with standard 24V control circuits\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e The OEM HT01CN241 transformer is wound and rated to exact Carrier factory specifications, ensuring stable 24V output under full load. Generic transformers may under-deliver VA capacity, causing erratic control board behavior or nuisance tripping of the built-in thermal fuse.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Difficulty: 2\/5\u003c\/strong\u003e — Shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Verify primary and secondary voltages with a multimeter after installation before restoring the system to service.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before cutoff.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the Carrier \u003cstrong\u003eFX4BNF042000AAAA\u003c\/strong\u003e air handler. Verify your existing transformer's VA rating and primary\/secondary voltages on the unit's data plate before ordering to ensure correct fitment. Our parts specialists are available to confirm compatibility before you buy — same-day shipping means you're back up and running fast.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909487382899,"sku":"CARRIE-FX4BNF042000AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909487415667,"sku":"CARRIE-FX4BNF042000AAAA-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_9df4a4e0-72e4-4ac0-a110-c905c80dcad7.jpg?v=1782941915","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fx4bnf042000aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}