{"product_id":"carrier-m150039mx41011525-transformer-h306bq","title":"OEM Carrier Transformer 40VA 120V\/24V for M150039MX41011525","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V\/24V for Model M150039MX41011525\u003c\/h1\u003e\u003cp\u003eThis OEM replacement transformer (part number \u003cstrong\u003eHT01BD118\u003c\/strong\u003e) is the factory-specified control circuit transformer for the \u003cstrong\u003eCarrier M150039MX41011525\u003c\/strong\u003e. The transformer steps down line voltage (120V) to the 24V signal voltage required to power the control board, thermostat, and all low-voltage switching circuits. When this component fails, the entire control circuit goes dark — you'll see a blank thermostat, no response from the system, or a tripped low-voltage fuse that immediately blows again upon replacement.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e Primary: 120V AC | Secondary: 24V AC | VA Rating: 40VA | OEM Part Number: HT01BD118 | Factory-matched windings and thermal protection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers from Carrier are wound to exact VA and voltage tolerances, ensuring stable 24V output under full control-circuit load. Generic alternatives often exhibit voltage sag under load, which can cause erratic board behavior, false fault codes, and premature contactor coil failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker and confirm zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, wire nuts or spade connectors, multimeter. Label all wiring before disconnecting. Verify 24V output at secondary terminals after installation before restoring full system power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before cutoff ship same business day from our stocked warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed for the Carrier \u003cstrong\u003eM150039MX41011525\u003c\/strong\u003e. Always confirm your unit's control circuit voltage and VA requirements on the equipment data plate before ordering. If your thermostat is unresponsive or your low-voltage fuse keeps blowing, this transformer is the most likely root cause. Our fitment team is available to verify compatibility before you order — don't guess on a control circuit component.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909286580595,"sku":"CARRIE-M150039MX41011525-TRANSFORMER-HT01BD118","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909286613363,"sku":"CARRIE-M150039MX41011525-TRANSFORMER-HT01BD118-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-HT01BD118_835d430a-5d0e-4751-b341-c1540110db64.jpg?v=1782941745","url":"https:\/\/nationalhvacparts.com\/products\/carrier-m150039mx41011525-transformer-h306bq","provider":"National HVAC Parts","version":"1.0","type":"link"}