York 3400-3151 Limit Switch

The York S1-3400-3151 Limit Switch is a critical safety component designed for high-limit thermal protection in residential and commercial HVAC systems. This OEM replacement part is engineered to monitor furnace plenum temperatures, specifically calibrated with an open point of 175°F and a close point of 125°F. As an automatic reset limit switch, it eliminates the need for manual intervention once temperatures return to safe operating parameters. Technicians frequently utilize this L175-50 furnace limit in York, Coleman, Evcon, and Luxaire equipment to prevent heat exchanger damage and ensure system integrity. The 1-pole configuration and durable construction meet the rigorous demands of HVAC high-limit safety standards. When troubleshooting intermittent blower operation or complete system lockout, verifying the continuity of this temperature-actuated switch is a standard diagnostic step. For optimal performance in electric furnaces, it is professional best practice to inspect all limit switches in the circuit simultaneously to ensure consistent thermal response across the heating cycle.

• Precise Thermal Regulation: Features a fixed 175°F trip point to prevent over-temperature conditions in the heat exchanger.
• Automatic Reset Functionality: Closes the circuit automatically at 125°F, reducing unnecessary service calls for manual resets.
• Broad Compatibility: Serves as a direct OEM replacement for older York and Coleman part numbers, including 3400-315 and 3400-3151.
• Safety Compliance: Built to meet original equipment manufacturer specifications for reliable high-limit safety cut-out performance.

What causes a York S1-3400-3151 limit switch to trip frequently?
Frequent tripping is typically systemic. Check for restricted airflow caused by dirty filters, blocked return air ducts, or a failing blower motor, which leads to plenum temperatures exceeding the 175°F threshold.

Can I replace an L175-50 switch with a different temperature rating?
No. For safety and equipment protection, always match the original temperature specifications (175°F Open / 125°F Close) provided by the manufacturer.

Is this switch compatible with Coleman electric furnaces?
Yes, the S1-3400-3151 is a standard high-limit component commonly used across York, Coleman, and Luxaire electric heating units.

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.