OEM Lennox Limit Switch — 20J83
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The genuine OEM Lennox 20J83 limit switch is a high-temperature safety control that protects your furnace and home from overheating. Mounted on the heat exchanger or plenum, it monitors supply-air temperature and opens the circuit to shut off the gas valve if temperatures climb beyond a safe threshold — typically due to restricted airflow.
Common failure symptoms: A tripped or failing 20J83 commonly causes the furnace to shut down on high limit, short cycle, or run the blower continuously with no heat. Because the switch often trips in response to a dirty filter, blocked ducts, or a weak blower, a limit fault can also flag an underlying airflow problem worth checking.
Why OEM matters: Each Lennox limit switch is calibrated to a precise trip and reset temperature matched to your furnace's heat exchanger and cabinet design. An aftermarket switch with the wrong set point can nuisance-trip or, worse, fail to open when it should. The factory 20J83 ensures the exact temperature rating, correct mounting fit, and dependable overheat protection your Lennox system requires.
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