{"product_id":"carrier-py4gnaa42090aa-transformer-h30291","title":"OEM Carrier Control Transformer 40VA 208\/240V–24V — PY4GNAA42090AA","description":"\u003ch1\u003eOEM Carrier Control Transformer 40VA 208\/240V to 24V for Model PY4GNAA42090AA\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the \u003cstrong\u003eCarrier PY4GNAA42090AA\u003c\/strong\u003e packaged unit. The transformer steps down line voltage (208\/240V) to the 24V signal used by your thermostat, control board, contactor coil, and every other low-voltage component in the system. When this part fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any call for heating or cooling, and no fault 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 capacity | 208\/240V primary | 24V secondary | 50\/60 Hz | OEM part #HT01BD209 | Replaces HT01BD207, HT01CN232, 9076-00\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Generic units often use thinner windings and lower-grade core laminations, leading to premature thermal failure and control circuit instability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Always shut off power at the breaker and confirm with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, wire strippers, multimeter. Label or photograph all wire connections before disconnecting the old unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM manufacturer warranty. Ships same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered for the Carrier \u003cstrong\u003ePY4GNAA42090AA\u003c\/strong\u003e packaged unit. Verify your unit's model and serial number on the data plate before ordering. Cross-reference part numbers HT01BD207, HT01CN232, or 9076-00 if you are replacing an older unit. Questions about fitment? Our HVAC parts specialists verify compatibility before you order — in stock and ships today.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62640331161971,"sku":"CARRIE-PY4GNAA42090AA-TRANSFORMER-HT01BD209","price":50.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62640331194739,"sku":"CARRIE-PY4GNAA42090AA-TRANSFORMER-HT01BD209-GEN","price":44.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-HT01BD209_92405930-3033-4d52-b676-5e3281910f78.jpg?v=1775025822","url":"https:\/\/nationalhvacparts.com\/products\/carrier-py4gnaa42090aa-transformer-h30291","provider":"National HVAC Parts","version":"1.0","type":"link"}