{"product_id":"20604","title":"Transformer 40VA 120\/208\/240V to 24V Replacement – NBK-20604","description":"\u003ch2\u003eTransformer 40VA – 120\/208\/240V to 24V Replacement – NBK-20604\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eNBK-20604 Transformer\u003c\/strong\u003e is a reliable replacement component used in HVAC systems requiring a \u003cstrong\u003e40VA step-down transformer\u003c\/strong\u003e to convert high-voltage input into a stable \u003cstrong\u003e24V output\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eThis transformer replaces \u003cstrong\u003eMars 50354\u003c\/strong\u003e and is also compatible with \u003cstrong\u003ePackard PF42440\u003c\/strong\u003e, making it an ideal solution for restoring proper low-voltage power to thermostats, relays, and control boards.\u003c\/p\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e40VA Power Rating:\u003c\/strong\u003e Suitable for many HVAC control applications\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-Voltage Input:\u003c\/strong\u003e Supports 120V, 208V, and 240V primary connections\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e24V Output:\u003c\/strong\u003e Provides consistent low-voltage power for system controls\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect Replacement:\u003c\/strong\u003e Replaces Mars 50354 and Packard PF42440\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHVAC Ready:\u003c\/strong\u003e Designed for furnaces, air handlers, and other control circuits\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSKU:\u003c\/strong\u003e 20604\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e HVAC, Miscellaneous\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Brand:\u003c\/strong\u003e Mars\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplaces OEM:\u003c\/strong\u003e 50354\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVoltage:\u003c\/strong\u003e 120\/208\/240V Primary → 24V Secondary\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRating:\u003c\/strong\u003e 40VA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eDirect Replacement For\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMars:\u003c\/strong\u003e 50354\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackard:\u003c\/strong\u003e PF42440\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhy Choose NBK-20604?\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eNBK-20604 Transformer\u003c\/strong\u003e ensures dependable low-voltage power delivery for HVAC control systems. It’s an essential replacement when troubleshooting power loss to thermostats, relays, or ignition\/control boards.\u003c\/p\u003e\n\u003ch3\u003eInstallation Tips\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eTurn off all power at the breaker before installation.\u003c\/li\u003e\n\u003cli\u003eConfirm input voltage matches your system wiring (120V, 208V, or 240V).\u003c\/li\u003e\n\u003cli\u003eSecure transformer mounting to reduce vibration and wear.\u003c\/li\u003e\n\u003cli\u003eCheck for proper 24V output before restoring full system operation.\u003c\/li\u003e\n\u003cli\u003eConsult a licensed technician if wiring is uncertain.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003ePairs Well With\u003c\/h3\u003e\n\u003cp\u003eThermostats, Control Boards, Ignition Modules, Limit Switches, HVAC Relays\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSPECIAL ORDER NOTICE:\u003c\/strong\u003e This item is sourced through our special order program. Please allow 1–2 business days for processing prior to shipment.\u003c\/p\u003e","brand":"Mars","offers":[{"title":"Default Title","offer_id":52401227497840,"sku":"SO-20604","price":25.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0595\/4463\/3444\/files\/20604-50354.webp?v=1771196499","url":"https:\/\/total-hearth.com\/products\/20604","provider":"Total Hearth","version":"1.0","type":"link"}