Lennox 71G17 Vent Switch

The Lennox 71G17 Vent Switch is a critical safety component designed for precise thermal monitoring in high-efficiency HVAC systems. Engineered as a 300F manual reset limit switch, this device serves as a primary defense against dangerous flue obstructions or heat exchanger failures. When vent temperatures reach the 300-degree Fahrenheit threshold, the internal circuit opens, instantly terminating the gas valve signal to prevent carbon monoxide spillage and equipment damage. This OEM Lennox replacement part carries an orange dot identifier and is a direct substitute for the 71G1701, ensuring seamless mechanical and electrical integration for field service technicians. Built with a normally closed (NC) configuration and a manual reset button, it requires a physical inspection of the venting system before operation can be restored, adhering to strict safety protocols. This switch is frequently utilized in G17 series furnaces and various residential heating units where reliable rollout and blockage detection are non-negotiable for system uptime.

• Precise Thermal Trip Point: Actuates at 300 degrees Fahrenheit (+/- 14°F) to provide rapid response during vent blockage or rollout conditions.
• Direct OEM Compatibility: Serves as the factory-authorized replacement for Lennox 71G1701 and 71G18, maintaining original equipment specifications.
• Manual Reset Safety: Featuring a manual reset mechanism that prevents automatic cycling, forcing a necessary safety inspection by a technician.
• Durable Construction: Specifically designed to withstand demanding furnace environments without premature fatigue or nuisance tripping.

How do I identify the Lennox 71G17 in the field?
This switch is typically identified by an orange dot on the face of the component and the 300F temperature rating stamped on the bracket. It replaces older part numbers including 71G1701 and 26H99.

What causes this switch to trip repeatedly?
Repeated tripping usually indicates a genuine blocked vent, a failing draft inducer motor, or a cracked heat exchanger. Always check the flue pipe for debris or bird nests before resetting the manual reset switch.

Can this be used as a universal rollout switch?
While the form factor is common, this limit control rollout switch is calibrated for a specific 300°F threshold. It should only be used as a replacement for parts with identical thermal profiles to ensure proper safety sequencing.

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.