{"product_id":"carrier-fx4dnf031t00aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V-24V for FX4DNF031T00AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V to 24V for Model FX4DNF031T00AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM replacement transformer (part# \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) is the factory-specified control transformer for the \u003cstrong\u003eCarrier FX4DNF031T00AAAA\u003c\/strong\u003e air handler. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage safety circuits. When it fails, the entire control circuit goes dead — your thermostat goes blank, the system will not respond to any call for heating or cooling, and no error codes will display because the board itself has lost power.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01CN241 | Factory-matched impedance and thermal protection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This factory OEM unit is wound to exact VA and impedance tolerances for the FX4DNF031T00AAAA control circuit. Undersized or off-tolerance generic transformers can trip their thermal cutout repeatedly or fail to hold voltage under full contactor load, causing intermittent lockouts and premature control board failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off all power at the breaker and air handler disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, wire nuts or spade terminals, multimeter. Photograph all low-voltage wiring connections before disconnecting. Verify 24V output with a multimeter after installation before restoring full power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. In-stock units ship same business day from our warehouse when ordered before 3 PM local time.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the Carrier \u003cstrong\u003eFX4DNF031T00AAAA\u003c\/strong\u003e fan coil air handler. Always verify your existing transformer's VA rating and primary\/secondary voltage on the unit data plate or transformer label before ordering. If your system shares a transformer with a furnace or heat pump control board, confirm load requirements have not changed. Our parts specialists are available to verify fitment before you order — no guesswork.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909476569459,"sku":"CARRIE-FX4DNF031T00AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909476602227,"sku":"CARRIE-FX4DNF031T00AAAA-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_3d040131-73f8-4071-b0ad-9afb796989c9.jpg?v=1782939679","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fx4dnf031t00aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}