OEM Lennox Limit Switch — 38M67
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The genuine OEM Lennox 38M67 limit switch is a temperature-activated safety device that protects your Lennox furnace from dangerous overheating. Mounted at the heat exchanger or plenum, it opens the burner control circuit the moment internal temperatures rise above the safe threshold — a situation most often triggered by restricted airflow, a dirty filter, or a struggling blower motor.
Common failure symptoms: The furnace short-cycles during a heat call, burners light and then cut off prematurely, there is no heat output, or the blower runs nonstop. A 38M67 that fails in the open position prevents the furnace from heating, while one stuck closed leaves the heat exchanger unprotected against overheating and cracking.
Why OEM matters: The Lennox 38M67 is factory-calibrated to the exact open and close temperatures your furnace requires. Generic replacements with mismatched temperature ratings can permit unsafe conditions or cause frustrating nuisance lockouts. The OEM part delivers correct calibration, exact fit, and the reliable safety performance Lennox engineered into your system.
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