Lennox 47K18 Rollout Switch

The Lennox 47K18 Rollout Switch is a critical safety component engineered for forced-air furnaces and industrial heating systems, designed to interrupt the burner circuit if flame rollout or excessive heat is detected. This OEM Lennox rollout switch features an SPST (Single Pole Single Throw) configuration and is factory-calibrated to actuate at 400 degrees Fahrenheit. As a safety-limit device, it utilizes a manual reset mechanism, requiring a technician to physically inspect the heat exchanger and burner assembly for venting issues or blockages before restoring operation. The 45-degree quick-connect terminals ensure a secure, low-resistance electrical connection, while the robust green-coded housing allows for rapid identification in the field. This 400F thermal switch is a direct replacement for various Lennox HVAC safety switches where high-limit thermal protection is required to prevent equipment damage and ensure a safe combustion environment. Its reliability and precision make it an essential furnace replacement part for maintaining system integrity according to manufacturer specifications.

• Precision Thermal Monitoring: Actuates strictly at 400°F (+/- 20°F) to provide a reliable failsafe against high-temperature conditions in the burner vestibule.
• Manual Reset Safety: Ensures that the root cause of high-limit tripping, such as a cracked heat exchanger or flue blockage, is addressed by a professional before the system restarts.
• OEM Compatibility: Genuine Lennox replacement part ensures exact fitment and electrical alignment with existing furnace control boards and safety loops.
• Industrial-Grade Construction: Built with heavy-duty materials to withstand the localized heat environment of residential and industrial HVAC machinery.

• Can I bypass this switch to test the furnace? No. Bypassing a flame rollout switch is a significant safety hazard. If the switch has tripped, the combustion process must be inspected for proper drafting and heat exchanger integrity.
• How do I identify this specific limit? The Lennox 47K18 is identifiable by its green color coding and the 400F temperature stamp on the mounting bracket or housing.
• Does the orientation of the terminals matter? While the SPST contact is non-polarized, the 45-degree terminals are designed for specific clearance within the Lennox burner compartment to prevent wire fatigue and short circuits.

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.