Copeland Comfort Control (White Rodgers) 3L09-12 Limit Switch

The Copeland Comfort Control (White-Rodgers) 3L09-12 Limit Switch is a high-reliability 1/2" bimetal disc limit control engineered for precision high-limit protection in residential and commercial furnaces. This board-mounted HVAC limit switch features a fixed open temperature of 220°F and a fixed close temperature of 180°F. Operating on an open-on-rise switch action, it serves as a critical safety component to prevent heat exchanger damage or hazardous overheating conditions. As a direct 626435R cross reference, this Type 36T (Style 612722) thermal disc ensures seamless integration into existing control boards. The 3.12" insertion length allows for accurate sensing within the plenum air stream, while the auto reset functionality allows the system to resume normal operation once the temperature drops below the 180°F threshold.

Key Benefits for Professionals

• OEM Compatibility: Authentic White-Rodgers/Copeland component designed as a drop-in replacement for Therm-O-Disc Style 612722 applications.
• Precise Thermal Calibration: Fixed 220 degree F cut-out ensures the system stays within safe operating parameters without the drift common in lower-quality aftermarket switches.
• Durable Board Mount Design: Features a board-mounted 1/2" bimetal disc for stable installation and consistent vibration resistance in high-airflow environments.
• Rugged Construction: Built to handle the thermal cycling demands of modern high-efficiency furnaces and HVAC equipment.
• Streamlined Installation: The standard 3L09-12 footprint and 3.12-inch probe length facilitate fast field replacements to minimize equipment downtime.

Common Questions

Is the 3L09-12 an automatic or manual reset switch?
This is an auto reset limit switch. It will automatically re-close the circuit once the sensed temperature falls to 180°F, eliminating the need for a manual technician reset after a high-temperature event.

What does 'Open on Rise' mean for this furnace limit?
Open on Rise means the electrical contacts break (opening the circuit) when the temperature climbs to the 220°F setpoint, typically shutting down the gas valve or heating element to protect the system.

Can I use this as a replacement for the 626435R?
Yes, the 3L09-12 is the designated technical cross-reference for part number 626435R, matching its physical dimensions and thermal specifications.

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.