OEM Lennox Limit Switch — 33J61
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The genuine OEM Lennox 33J61 limit switch is a high-temperature safety control used in Lennox furnaces. It senses the temperature of the air passing over the heat exchanger and automatically shuts down the burner or heating element when temperatures exceed safe limits — a vital protection against cracked heat exchangers, overheated components, and fire hazards. Each 33J61 is set to the exact trip temperature Lennox engineered for your model.
Common failure symptoms include a furnace that short cycles, ignites then quickly shuts off, blows only cool air, runs the blower nonstop, or locks out with a limit-related fault code. A worn or drifted limit switch may trip early during normal operation or, worse, fail to open when the furnace genuinely overheats.
Why OEM matters: limit switches are safety devices where calibration is everything. The Lennox 33J61 matches the specified open and reset temperatures, terminal layout, and mounting for your furnace. Substituting a generic switch risks either nuisance lockouts or the loss of critical overheat protection. The factory part restores proper, safe operation exactly as designed.
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