{"product_id":"carrier-ff1dna030000aaaa-transformer-h3hww2","title":"OEM Carrier Transformer 40VA 120V\/24V for FF1DNA030000AAAA","description":"\u003ch1\u003eOEM Carrier Control Transformer 40VA for Model FF1DNA030000AAAA\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement control transformer (part number \u003cstrong\u003eHT01CN236\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier FF1DNA030000AAAA\u003c\/strong\u003e fan coil unit. The transformer steps down line voltage (120V) to the 24V signal voltage that powers your thermostat, control board, and all low-voltage switching circuits. When the transformer fails, the entire control circuit goes dead — the thermostat goes blank, no heating or cooling calls are processed, and the system will not respond in any mode. It is one of the first components to check when a system appears completely unresponsive.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched impedance and core construction for Carrier FF1DNA030000AAAA fan coil units\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e The OEM HT01CN236 transformer is wound to exact Carrier specifications, ensuring proper 24V output under full control-circuit load. Generic transformers may sag voltage under load, causing intermittent lockouts, nuisance tripping, or premature control board failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker before beginning. Tools needed: flat-head and Phillips screwdrivers, wire stripper, multimeter (verify 0V before touching wiring). Label or photograph all low-voltage wiring connections before disconnecting. Reconnect primary leads to line voltage last.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. In stock and ships the 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\u003eFF1DNA030000AAAA\u003c\/strong\u003e fan coil unit. Always verify your existing transformer's VA rating and primary\/secondary voltages against your unit's data plate before ordering. If you need fitment confirmation, our HVAC parts specialists are available to verify compatibility before you purchase — same-day shipping on all in-stock orders.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909515366771,"sku":"CARRIE-FF1DNA030000AAAA-TRANSFORMER-HT01CN236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909515399539,"sku":"CARRIE-FF1DNA030000AAAA-TRANSFORMER-HT01CN236-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-HT01CN236_c2594892-b938-4d2d-9f73-a06f5f6f10de.jpg?v=1782941006","url":"https:\/\/nationalhvacparts.com\/products\/carrier-ff1dna030000aaaa-transformer-h3hww2","provider":"National HVAC Parts","version":"1.0","type":"link"}