Lennox 52M74 Rollout Switch

The Lennox 52M74 Rollout Switch is a critical safety component designed for precise over-temperature protection in Lennox furnace units and residential HVAC systems. As a Single Pole Single Throw (SPST) switch, this manual reset flame rollout switch is engineered to interrupt the ignition circuit when it detects temperatures reaching the 320 degrees F threshold. This prevents hazardous conditions resulting from heat exchanger failure or flue blockages. This OEM replacement part (Manufacturer Number 52M74) ensures exact fitment and electrical compatibility for a wide range of Lennox models, including the AF80MPA and AFGP series. This switch operates on a "limit open on rise" action, requiring a physical reset by a technician once the thermal event is resolved and the system has cooled. Integrating this 320F rollout switch maintains the high-limit safety standards required for high-efficiency gas furnaces and packaged rooftop units, ensuring reliable circuit control during peak operation.

• System Protection: Provides an immediate safety cutoff at 320 degrees F to prevent equipment damage.
• Manual Reset Design: Ensures a technician inspects the system for airflow or venting issues before restarting.
• OEM Compatibility: Specifically designed as a direct Lennox 52M74 substitute for seamless installation.
• Durable SPST Contacts: Built with robust Single Pole Single Throw architecture for consistent electrical switching.

What causes a 320 degree rollout switch to trip?
A tripped 52M74 switch usually indicates restricted airflow, a cracked heat exchanger, or a blocked exhaust vent causing flames to "roll out" of the combustion chamber.

Is the Lennox 52M74 a universal HVAC part?
No, this is an OEM Lennox rollout switch. While it may fit various models within the Lennox and Armstrong brands, always verify the specific temperature rating and mounting footprint before installation.

Can I bypass a manual reset flame rollout switch for testing?
Bypassing safety switches is never recommended. If the 320F switch opens, the underlying thermal issue must be diagnosed and repaired by a qualified contractor to ensure safe operation.

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.