{"product_id":"carrier-py4gnaa30040aa-transformer-h30291","title":"OEM Carrier Control Transformer 40VA 208\/240V–24V for PY4GNAA30040AA","description":"\u003ch1\u003eOEM Carrier Control Transformer 40VA 208\/240V to 24V for Model PY4GNAA30040AA\u003c\/h1\u003e\u003cp\u003eThis factory-original OEM control transformer (part #HT01BD209) is the direct-fit replacement for the \u003cstrong\u003eCarrier PY4GNAA30040AA\u003c\/strong\u003e packaged unit. The transformer steps down high-voltage line power (208\/240V) to the 24V AC signal that energizes your system's entire control circuit — thermostat, contactor coils, gas valve, and control board alike. When this transformer fails, the result is typically a completely unresponsive system: the thermostat goes blank, no heating or cooling calls are answered, and the unit sits dead even with line voltage present at the disconnect.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e Input 208\/240V | Output 24V secondary | 40VA power rating | 50\/60Hz | OEM part number HT01BD209 | Factory-matched Carrier specification\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound and insulated to exact Carrier factory tolerances. Generic or aftermarket units frequently run outside ±5% voltage output tolerance, which can cause nuisance tripping of downstream boards and shorten contactor coil life.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Always shut off line-voltage power at the disconnect and verify zero volts with a multimeter before touching any wiring. Photograph all wiring connections before disconnecting the old transformer. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Re-verify 24V output after install before closing the cabinet.\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 Direct OEM replacement for \u003cstrong\u003eCarrier PY4GNAA30040AA\u003c\/strong\u003e packaged units. Always confirm your unit's data plate voltage matches the 208\/240V primary specification before ordering. Need fitment help? Our HVAC parts specialists verify compatibility before you buy — contact us today.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62640333160819,"sku":"CARRIE-PY4GNAA30040AA-TRANSFORMER-HT01BD209","price":55.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62640333193587,"sku":"CARRIE-PY4GNAA30040AA-TRANSFORMER-HT01BD209-GEN","price":48.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-HT01BD209_bc34cb7f-04b4-4a95-a1f7-cd2b3427be9b.jpg?v=1775025740","url":"https:\/\/nationalhvacparts.com\/products\/carrier-py4gnaa30040aa-transformer-h30291","provider":"National HVAC Parts","version":"1.0","type":"link"}