York S1-025-30861-000 Limit Switch

The York S1-025-30861-000 Limit Switch is a critical safety component engineered for HVAC furnace applications requiring precise thermal monitoring. This OEM York replacement part features an automatic reset mechanism designed to protect the heat exchanger and internal components from high-limit conditions. With a 3-inch probe, this 145-175F auto limit switch is calibrated to open at 175°F to interrupt the heating circuit and automatically close (reset) once the temperature drops to 145°F. Utilizing a bimetal temperature sensor, it ensures consistent performance and system reliability in residential and light commercial equipment. This specific furnace high limit switch is often identified by cross-reference model 1NP0442 and is common in York, Coleman, and Luxaire gas-fired units. For field technicians, the 3-inch insert depth and flat mounting flange provide a direct fit for most compatible furnace plenums, eliminating the need for structural modifications during emergency repairs or routine maintenance.

• Precise Thermal Protection: Engineered with a 175°F opening threshold to prevent heat exchanger damage and ensure safe operating parameters.
• Automatic Reset Logic: Eliminates manual intervention by resetting the circuit once the system cools to 145°F, maintaining heating continuity.
• Simplified Installation: Standard 3-inch insert depth and pre-drilled mounting flange facilitate a faster swap in the field for contractors.
• OEM Standards: Manufactured to original factory specifications for exact electrical and mechanical compatibility with York/Coleman systems.

What causes a limit switch to trip repeatedly?
Frequent cycling (tripping) is often caused by restricted airflow, such as a dirty air filter, blocked return vents, or an undersized duct system, which forces the heat exchanger to reach the 175°F limit.

Can this replace a manual reset limit switch?
No. This is an automatic reset switch. Safety protocols require that you always replace a limit control with the same reset type and temperature rating specified by the equipment manufacturer.

How do I verify if the 3-inch insert is right for my furnace?
Measure the distance from the mounting surface to the tip of your existing probe; this 3-inch model is designed for specific plenum depths to ensure the sensor is positioned in the direct path of the airflow.

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.