{"product_id":"carrier-hb1bjx036000aaaa-transformer-h4oyjb","title":"OEM Carrier Transformer 40VA 120V–24V for HB1BJX036000AAAA","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer for Model HB1BJX036000AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier transformer (part# \u003cstrong\u003eHT01AW229\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eHB1BJX036000AAAA\u003c\/strong\u003e unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, contactor coil, and control board. When it fails — whether from a shorted control wire, a blown secondary fuse, or simply age — nothing in the system responds: no fan, no heat, no cooling, no thermostat communication. A failed transformer is often misdiagnosed as a board failure, making it the smart first component to test and replace.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | 120V primary \/ 24V secondary | Class 2 control circuit transformer | Factory-matched impedance for stable control voltage under load\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers like this HT01AW229 are wound to exact VA and voltage specs for this unit. Generic units may under-deliver VA under load, causing nuisance lockouts, chattering contactors, or premature control board failure.\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, multimeter (verify 0V at primary before touching wires). Label or photograph all control wiring before disconnecting. Total job time: 20–30 minutes for most technicians.\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 warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed for the Carrier \u003cstrong\u003eHB1BJX036000AAAA\u003c\/strong\u003e unit using OEM part number HT01AW229. Confirm your existing transformer's VA rating and primary\/secondary voltages on the data plate before ordering to ensure a drop-in fit. Our parts specialists are available to verify compatibility before you buy — no guesswork required.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909348708723,"sku":"CARRIE-HB1BJX036000AAAA-TRANSFORMER-HT01AW229","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909348741491,"sku":"CARRIE-HB1BJX036000AAAA-TRANSFORMER-HT01AW229-GEN","price":18.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-HT01AW229_2006f840-210b-44a6-a289-8ad2ba3cc9dd.jpg?v=1782941938","url":"https:\/\/nationalhvacparts.com\/products\/carrier-hb1bjx036000aaaa-transformer-h4oyjb","provider":"National HVAC Parts","version":"1.0","type":"link"}