Lennox 45H83 Limit Switch

The Lennox 45H83 Limit Switch is a critical OEM replacement part engineered for high-temperature thermal protection within residential and commercial HVAC systems. As an automatic reset limit switch, this component is factory-calibrated to trip between 200°F and 230°F, effectively interrupting the electrical circuit to the burner or heating elements if internal temperatures exceed safe operating parameters. Designed for 24V or 240V control circuits, this furnace high limit switch features a 3/8-inch NPT connection and a round body configuration, ensuring a precise fit in supply plenums and heat exchanger assemblies.

For technicians troubleshooting short-cycling furnaces or intermittent shutdown issues, the Lennox 45H83 (part number 45H8301) provides reliable system monitoring without the need for manual intervention after cooling. Integrating this thermal limit safety switch preserves equipment integrity by preventing heat exchanger stress and ensuring compliance with manufacturer safety standards. Whether you are performing a furnace limit switch replacement or a routine system tune-up, using genuine Lennox heating parts ensures compatibility and maintains the original engineering specifications of the unit.

• Precision Thermal Monitoring: Actuates strictly within the 200°F to 230°F range to prevent catastrophic overheating.
• Automatic Reset Functionality: Disengages once temperatures return to a safe level, reducing unnecessary service calls for simple over-temp spikes.
• OEM Compatibility: Specifically designed as a direct replacement for Lennox 45H8301, ensuring proper terminal alignment and mounting.
• Robust Construction: Built with high-grade materials to withstand the rigorous cycling of industrial and residential heating environments.

• How do I know if my limit switch is faulty? Professional diagnostics typically involve checking for continuity across terminals while the system is cool; a "stuck open" switch often causes the blower to run continuously without burner ignition.
• Will this switch work in other furnace brands? While designed for Lennox equipment, compatibility is determined by the temp rating and mounting style. Always verify the L-rating on the existing part.
• What causes this switch to trip frequently? Common culprits include restricted airflow from dirty filters, a failing blower motor, or blocked return air vents.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.