Lennox 11G87 Limit Switch

The Lennox 11G87 Limit Switch is a critical safety component designed for precise thermal regulation within residential and commercial HVAC systems. This 90-120F AUTO Limit Switch functions as a high-limit security measure, automatically interrupting the burner circuit if internal plenum temperatures exceed 120°F and resetting once the system cools to 90°F. Engineered for longevity, this genuine Lennox OEM replacement part ensures your furnace operates within factory-specified parameters, protecting the heat exchanger from cracks and preventing hazardous overheating conditions. As a Lennox furnace high limit switch, the 11G87 is compatible with a wide range of G12, G14, G17, and G20 series units, as well as equipment from Allied, Armstrong, and Ducane. For technicians performing HVAC limit switch troubleshooting, this auto-reset control eliminates the need for manual intervention after a temporary airflow restriction, though repeated trips typically indicate a clogged filter or a failing blower motor. Replace your faulty 11G8701 limit control with this factory-spec component to maintain system integrity and restore reliable heating cycles.

• OEM Precision: Ensures exact fit and function as a direct 11G8701 replacement, maintaining the original safety ratings of your Lennox equipment.
• Automatic Reset: Features a 90°F to 120°F operating range with an auto-reset function to restore system operation after cooling.
• Broad Compatibility: Supports various Lennox, Armstrong, and Ducane furnace models, including G12RD, G17RQ, and G20R series.
• Thermal Protection: Prevents heat exchanger damage by strictly monitoring discharge air temperatures.

• How do I know if my Lennox 11G87 limit switch is bad? If your furnace blower runs constantly but the burners won't ignite, or the system cycles off before reaching the thermostat setpoint, the limit switch may be stuck open or tripping due to high internal heat.
• Can I use a higher temperature limit switch instead of the 11G87? No. You must use the 90-120F rated part specified by the manufacturer. Installing a switch with a higher limit poses a significant fire hazard and can lead to heat exchanger failure.
• Does this switch require a manual reset? No, this is an auto-reset limit switch. It will automatically close the circuit once the sensor temperature drops back down to the 90°F reset point.

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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.