OEM Lennox Hot Surface Ignitor — 25N42
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The genuine OEM Lennox 25N42 hot surface ignitor (HSI) is responsible for igniting the burners in your Lennox gas furnace. When a heating cycle begins, the control board sends voltage to the ignitor, heating its element until it glows and lights the gas flowing from the open valve. A properly functioning HSI is the foundation of safe, reliable, on-demand heat.
Common failure symptoms: The furnace attempts to start but never produces heat, you notice repeated ignition clicks followed by lockout, the ignitor fails to glow, or heat becomes intermittent. Hot surface ignitors are brittle and degrade over time from repeated thermal cycling, making them a leading cause of no-heat service calls.
Why OEM matters: The OEM Lennox 25N42 is engineered to the exact resistance, wattage, and mounting specifications of your Lennox furnace. Aftermarket alternatives can misfire, warp, or wear out quickly due to mismatched electrical characteristics. Installing the genuine Lennox part guarantees correct fit, proper ignition timing, and long-lasting performance.
Shipping Information
- Orders placed before 3PM CST ship same business day
- Standard delivery: 2-5 business days
- Express shipping available at checkout
- Free shipping on orders over $75
- Tracking number emailed upon shipment
Return Policy
- 30-day returns on unused parts in original packaging
- Electrical parts (capacitors, contactors, control boards) are final sale once installed
- Email info@nationalhvacparts.com to initiate a return
- Refunds processed within 5-7 business days