White-Rodgers 3L11-140 Limit Switch

The White-Rodgers 3L11-140 is a precision-engineered 1/2" bimetal disc thermostat designed for high-limit temperature control in residential and light commercial heating equipment. Built on the Therm-O-Disc Style 10848 platform (Type 36T22), this open-on-rise limit switch is calibrated to break the electrical circuit when temperatures reach the 135°F to 145°F (57°C to 63°C) range. With a fixed 30°F (17°C) differential, it ensures reliable system cycling and prevents overheating of the heat exchanger or plenum. This OEM replacement limit switch features high-speed contact separation for arc suppression and consistent thermal response. As a snap-action thermal control, it is frequently utilized in furnaces, unit heaters, and various HVACR applications requiring a SPST furnace limit switch. Its compact 1/2" disc footprint allows for easy mounting in tight airstream compartments, providing critical safety integration for a wide variety of HVAC platforms and appliance configurations.

• Precise Thermal Calibration: Factory-set for 135-145°F opening to match specific OEM safety requirements.
• Universal 1/2" Disc Fitment: Cross-compatible with numerous Type 36T22 style controls for faster truck-stock matching.
• Snap-Action Reliability: High-speed bimetal response ensures clean contact breaks and extends component longevity.
• Broad Electrical Rating: Engineered to handle standard 24V, 120V, and 240V pilot duty or power circuits.
• Industry Standard Construction: Built to White-Rodgers and Therm-O-Disc specifications for maximum field endurance.

Is the 3L11-140 a manual or automatic reset switch?
This model is an automatic reset control, meaning it will re-close the circuit once the temperature drops 30°F below the trip point.

What causes a bimetal limit switch to trip prematurely?
Repeated tripping is usually indicative of restricted airflow, such as a clogged filter, undersized ductwork, or a failing blower motor, rather than a sensor failure.

Can this be used as a flame roll-out switch?
Typically, roll-out switches require a manual reset for safety compliance. This automatic reset 3L11-140 is intended for high-limit or fan control 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.