OEM Lennox Limit Switch — 35K61
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The genuine OEM Lennox 35K61 limit switch is a critical high-temperature safety control used in Lennox gas and electric furnaces. It continuously monitors the temperature inside the heat exchanger compartment and interrupts the burner or heating element if the unit exceeds its safe operating limit, protecting your equipment and home from overheating.
Common failure symptoms: If the 35K61 fails, you may experience a furnace that short-cycles (turns on and off repeatedly), a blower that runs constantly, no heat output, or the unit locking out on a limit fault. A switch that trips prematurely or stays open is a common cause of intermittent no-heat calls.
Why OEM matters: Limit switches are precision-calibrated to a specific trip temperature for each Lennox furnace model. An OEM 35K61 guarantees the exact factory temperature rating, terminal configuration, and mounting fit — aftermarket substitutes risk nuisance trips or, worse, failure to trip when it counts. Protect your Lennox system's safety chain with the correct factory part.
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