{"product_id":"carrier-fx4dnb043t00aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V\/24V for FX4DNB043T00AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V to 24V for Model FX4DNB043T00AAAA\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier FX4DNB043T00AAAA\u003c\/strong\u003e air handler. The transformer steps down line voltage (120V) to low-voltage 24VAC, powering the entire control circuit — including the thermostat, contactor coil, and control board relay logic. When the transformer fails, the system goes completely unresponsive: the thermostat goes dark, no call for heating or cooling is processed, and the unit will not operate in any mode. A failed transformer is often the first suspect when nothing works and the circuit breaker is confirmed on.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | 120V primary \/ 24V secondary | Factory OEM matched to Carrier FX4DNB043T00AAAA | Part No. HT01CN241 | Hardwired leads for direct drop-in replacement\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound to exact VA and voltage tolerances specified by Carrier engineering. Undersized or off-tolerance generic units can overheat, trip internal fuses, or cause erratic control board behavior — problems that can be misdiagnosed as a failed board.\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, needle-nose pliers, multimeter (to verify 24V output after install). Label or photograph all wiring connections before disconnecting the old transformer.\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\u003eFX4DNB043T00AAAA\u003c\/strong\u003e air handler. Always verify your unit's data plate voltage and VA rating before ordering. If you are unsure of fitment, our parts specialists can confirm compatibility before you purchase — just reach out before placing your order.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909480206707,"sku":"CARRIE-FX4DNB043T00AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909480239475,"sku":"CARRIE-FX4DNB043T00AAAA-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_bb44dddd-cbdd-428d-a3b1-4f6c53b2c53d.jpg?v=1782941195","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fx4dnb043t00aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}