{"product_id":"carrier-fc4dnf018008aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V\/24V for FC4DNF018008AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V\/24V for Model FC4DNF018008AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM replacement transformer (part# HT01CN241) is the factory-specified control circuit transformer for the \u003cstrong\u003eCarrier FC4DNF018008AAAA\u003c\/strong\u003e fan coil unit. The transformer steps down 120V line voltage to the 24V signal voltage required to power the control board, thermostat, and all low-voltage switching components. When this transformer fails, the entire control circuit goes dark — your thermostat will be unresponsive, the system won't call for heating or cooling, and nothing will happen when you adjust the setpoint. It is one of the first components to check when a unit appears completely dead despite confirmed line voltage at the unit.\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-wound coil with thermal overload protection\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's engineering team. Undersized or off-tolerance aftermarket units can sag under load, causing nuisance lockouts, control board damage, or premature contactor failure downstream.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, needle-nose pliers. Test secondary output (should read 24–28V AC) before condemning the transformer. Label or photograph all low-voltage wiring connections prior to removal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our stocked warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed and factory-matched for the Carrier \u003cstrong\u003eFC4DNF018008AAAA\u003c\/strong\u003e fan coil unit. Verify OEM part number HT01CN241 against your unit's wiring diagram or data plate before ordering. Our parts specialists are available to confirm fitment — order with confidence and get back up and running today.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909523820915,"sku":"CARRIE-FC4DNF018008AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909523853683,"sku":"CARRIE-FC4DNF018008AAAA-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_1feec920-878e-4628-a9af-b89c13fddebc.jpg?v=1782940967","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fc4dnf018008aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}