OEM Lennox Furnace Limit Switch — 27J29
OEM Guaranteed
Same-Day Ship
30-Day Returns
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The genuine OEM Lennox 27J29 limit switch is a critical safety control that monitors internal furnace temperature and shuts down the burners if the heat exchanger area exceeds its safe operating threshold. Calibrated to the exact trip and reset points specified by Lennox, it protects your equipment and home from dangerous overheating caused by restricted airflow or blower failure.
A failing limit switch often reveals itself through short cycling, where the furnace ignites and then shuts off prematurely, no heat output, the blower running continuously, or nuisance lockouts on the control board. A switch that trips too early or sticks open can leave you without heat, while one that fails to open removes an essential layer of protection.
Using the OEM Lennox 27J29 is essential because its temperature calibration and mounting are designed specifically for your furnace model. Generic limit switches with incorrect trip ranges can allow unsafe operation or cause frustrating false trips. Installing the factory part restores proper safety response and reliable heating. In stock and ships same day when ordered before 3PM CST.
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