{"product_id":"payne-pa3gnaa42000aa-transformer-h30291","title":"OEM Payne Transformer 40VA 120V-24V for PA3GNAA42000AA","description":"\u003ch1\u003eOEM Payne Transformer 40VA 120V to 24V for Model PA3GNAA42000AA\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer (part number \u003cstrong\u003eHT01BD209\u003c\/strong\u003e) for the \u003cstrong\u003ePayne PA3GNAA42000AA\u003c\/strong\u003e packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage required to power the entire control circuit — including the thermostat, contactor coil, gas valve, and control board. When the transformer fails, the entire system goes dark: the thermostat loses power, no calls for heat or cooling are answered, and nothing turns on. It is often one of the first components to check when a system shows absolutely zero response.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | Primary: 120V | Secondary: 24V | OEM part number HT01BD209 | Direct drop-in replacement for factory unit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM transformer is wound to exact factory VA and voltage specifications, ensuring stable 24V output under full control-circuit load. Undersized or off-tolerance generic transformers can overheat, trip their internal breaker repeatedly, or deliver fluctuating voltage that causes erratic system behavior.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Note wire colors and terminal positions before removing the old transformer. Confirm 24V output with a multimeter after installation 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 Designed for the Payne \u003cstrong\u003ePA3GNAA42000AA\u003c\/strong\u003e packaged unit. Always verify your existing transformer's VA rating and primary\/secondary voltages on the unit's data plate or wiring diagram before ordering to confirm fitment. Have questions about compatibility? Our HVAC parts specialists are ready to verify the fit before you buy.\u003c\/p\u003e","brand":"Payne","offers":[{"title":"OEM","offer_id":62908905390451,"sku":"PAYNE-PA3GNAA42000AA-TRANSFORMER-HT01BD209","price":34.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62908905423219,"sku":"PAYNE-PA3GNAA42000AA-TRANSFORMER-HT01BD209-GEN","price":30.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-HT01BD209_3de34e81-d234-4ba6-8728-d47ad8aee481.jpg?v=1780718843","url":"https:\/\/nationalhvacparts.com\/products\/payne-pa3gnaa42000aa-transformer-h30291","provider":"National HVAC Parts","version":"1.0","type":"link"}