OEM Lennox Furnace Limit Switch — 69W37
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The genuine OEM Lennox 69W37 limit switch is a high-temperature safety control that keeps your Lennox furnace operating within safe limits. Mounted on the heat exchanger or plenum, it senses supply-air temperature and interrupts the burner circuit whenever the unit overheats, protecting the heat exchanger and preventing hazardous operating conditions.
Common failure symptoms: When the 69W37 fails, you may notice the furnace short cycling, no heat despite an ignition attempt, the blower running continuously, or a limit-open fault displayed by the control board. A switch that has opened permanently will prevent the burners from firing, leaving you without heat.
Why OEM matters: The 69W37 is calibrated to a precise temperature set point matched to your specific Lennox furnace. Only the factory OEM part guarantees the correct trip range, sensor accuracy, and exact fitment — ensuring safe, code-compliant operation and avoiding the nuisance trips or safety gaps common with mismatched generic replacements.
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