{"product_id":"payne-pa3znb042000ac-transformer-h30291","title":"OEM Payne Transformer 40VA 120V\/24V for PA3ZNB042000AC — HT01BD209","description":"\u003ch1\u003eOEM Payne Control Transformer 40VA for Model PA3ZNB042000AC — Part HT01BD209\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer (part# \u003cstrong\u003eHT01BD209\u003c\/strong\u003e) for the \u003cstrong\u003ePayne PA3ZNB042000AC\u003c\/strong\u003e air conditioning system. The transformer steps down 120V line voltage to the 24V signal used by your thermostat, contactor coil, and control board. When it fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to calls for cooling, and no error codes appear because the board itself has no power. It's one of the most overlooked failure points in HVAC diagnostics.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | 120V primary \/ 24V secondary | Class 2 transformer | Direct OEM replacement for part number HT01BD209\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e The OEM HT01BD209 is wound to Payne's exact VA rating and insulation class. Undersized aftermarket transformers frequently fail under full load — especially when multiple 24V accessories (humidifiers, zone boards, UV lights) are connected — leading to repeat callbacks and nuisance trips.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Power down the unit and verify voltage with a multimeter before disconnecting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Note wire colors and terminal labels before removing the old unit. Standard spade or screw terminals make reinstallation straightforward.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our climate-controlled warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed for the Payne \u003cstrong\u003ePA3ZNB042000AC\u003c\/strong\u003e split-system air conditioner. Verify your existing transformer's VA rating and primary\/secondary voltages on the data label before ordering. If your unit shares components with Carrier or Bryant models of the same platform, part number HT01BD209 may cross-apply — contact our fitment team to confirm. In stock and ready to ship today — get your system's control circuit back online fast.\u003c\/p\u003e","brand":"Payne","offers":[{"title":"OEM","offer_id":62908878717299,"sku":"PAYNE-PA3ZNB042000AC-TRANSFORMER-HT01BD209","price":34.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62908878750067,"sku":"PAYNE-PA3ZNB042000AC-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_55689ef8-30d9-45eb-a021-bce2418d26c3.jpg?v=1780719002","url":"https:\/\/nationalhvacparts.com\/products\/payne-pa3znb042000ac-transformer-h30291","provider":"National HVAC Parts","version":"1.0","type":"link"}