OEM Lennox Limit Switch — 56W25
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The genuine OEM Lennox 56W25 limit switch is a temperature-sensing safety control for your Lennox gas furnace. Mounted near the heat exchanger, it continuously monitors plenum temperature and interrupts power to the burners whenever heat rises above the safe operating limit — typically caused by restricted airflow, a dirty filter, or blower failure. The 56W25 is factory-set to the specific trip temperature your Lennox model was designed around.
Common failure symptoms: A degraded 56W25 commonly produces short cycling, where the furnace fires and then shuts down after a short run, or nuisance high-limit lockouts even when airflow is normal. You may also see the blower running non-stop, intermittent no-heat episodes, or the furnace failing to complete a full heat cycle.
Why OEM matters: As a safety-critical component, the limit switch must open at exactly the right temperature. Generic replacements with incorrect trip points can either shut the system down needlessly or fail to protect the heat exchanger from dangerous overheating. The OEM 56W25 delivers the precise calibration, ratings, and fit Lennox intended, safeguarding both performance and safety.
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