Lennox 52M73 Rollout Switch

The Lennox 52M73 is a critical safety component designed for furnace flame rollout protection in residential heating systems. As a genuine OEM rollout switch, it monitors the burner area for abnormal temperature spikes typically caused by flue obstructions, cracked heat exchangers, or insufficient combustion air. This SPST (Single Pole Single Throw) limit is factory-calibrated to trip at 350 degrees F, immediately interrupting the ignition circuit to prevent hazardous operating conditions.

Engineered for high-reliability applications, this switch features a manual reset mechanism, requiring a technician to inspect the system and identify the root cause of the thermal event before restoring operation. The 52M73 is the direct replacement for Lennox 52M7301, as well as part numbers 70L56, 70L5601, and Allied Air R20017402. Its robust construction ensures precise thermal response and durable field performance in high-cycle environments.

Key Benefits:

• Direct OEM Match: Provides an exact fit and verified performance for Lennox, Armstrong, and Ducane equipment, including models like AF92MPE050U2-01 and AF90MPE100U4-B-01.
• Critical Safety Protection: Rapidly detects flame rollout to protect the equipment and structure from overheating or fire hazards.
• Standardized Specs: Rated for 350°F with a standard SPST configuration for seamless integration into existing safety loops.
• Manual Reset Feature: Ensures mandatory system inspection following a trip, upholding rigorous safety protocols.

Common Questions:

How do I test if my Lennox 52M73 rollout switch is bad?
After ensuring the reset button is depressed, check for continuity across the terminals using a multimeter. If the circuit remains open at room temperature, the internal bimetal disc has failed and the component must be replaced.

What causes a 350-degree rollout switch to trip?
Tripping is usually indicative of a blocked flue, a restricted heat exchanger, or draft issues that force heat and flames back toward the burner compartment rather than through the venting system.

Is the 52M73 compatible with 52M7301?
Yes, the 52M73 and 52M7301 are identical components and are interchangeable across all documented Lennox and Allied Air applications.

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.