OEM Lennox Limit Switch — 36M63
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30-Day Returns
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The genuine OEM Lennox 36M63 limit switch is a critical safety control that monitors the temperature inside your Lennox furnace and shuts off the burners if the heat exchanger gets too hot. Calibrated to Lennox's precise trip and reset points, it protects your equipment and home from overheating while allowing normal heating cycles to run uninterrupted.
Common failure symptoms: When a limit switch fails or drifts out of calibration, you may see the furnace short-cycling, the burners lighting then shutting off quickly, no heat with the blower running continuously, or a persistent limit-related fault code. A switch stuck open blocks ignition entirely, while a lazy switch can allow unsafe temperatures.
Why OEM matters: Limit switches are a safety device, and the trip temperature must match your furnace exactly. The factory-specified 36M63 carries the correct rating, sensor length, and mounting for your Lennox model — a mismatched aftermarket switch can nuisance-trip or, worse, fail to protect the unit. Keep your furnace safe with the part Lennox engineered for it. In stock and ready to ship same day.
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