{"product_id":"carrier-ph12na042000agaa-transformer-h4oyjb","title":"OEM Carrier 40VA Transformer 120V\/24V for PH12NA042000AGAA","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer 120V\/24V for Model PH12NA042000AGAA\u003c\/h1\u003e\u003cp\u003eThis OEM control transformer (part #HT01AW229) is the factory-specified replacement for the \u003cstrong\u003eCarrier PH12NA042000AGAA\u003c\/strong\u003e packaged heat pump unit. The transformer steps down 120V line voltage to the 24V used by the low-voltage control circuit — powering your thermostat, contactor coil, reversing valve, and safety switches. When this transformer fails, the entire control circuit goes dead: the thermostat goes blank, the system makes no response to any call for heating or cooling, and no safety fault codes are generated because the board itself has lost power.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e Input: 120V AC | Output: 24V AC | VA Rating: 40VA | Factory OEM part #HT01AW229 | Direct plug-in replacement with original wiring harness connectors\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e The OEM HT01AW229 transformer is wound and rated to exact Carrier factory specifications, ensuring precise 24V output under full VA load. Generic transformers often use thinner windings that sag under peak current draw, causing nuisance lockouts and board voltage instability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Difficulty: 2\/5\u003c\/strong\u003e — Shut off all power to the unit before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 0V before touching terminals). Label all low-voltage wires before disconnecting. Recheck output voltage after installation before re-energizing the full system.\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 Direct OEM replacement for Carrier model \u003cstrong\u003ePH12NA042000AGAA\u003c\/strong\u003e packaged heat pump. Verify primary input voltage and VA rating on your unit's data plate before ordering. Our fitment team is available to confirm compatibility — reach out before you order if you have any questions.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62641951801715,"sku":"CARRIE-PH12NA042000AGAA-TRANSFORMER-HT01AW229","price":35.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62641951834483,"sku":"CARRIE-PH12NA042000AGAA-TRANSFORMER-HT01AW229-GEN","price":30.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-HT01AW229_2ad5fa50-393b-45e1-b152-f689a6b1010a.jpg?v=1775016334","url":"https:\/\/nationalhvacparts.com\/products\/carrier-ph12na042000agaa-transformer-h4oyjb","provider":"National HVAC Parts","version":"1.0","type":"link"}