York S1-7990-3591 Limit Switch

For technicians servicing York, Coleman, or Luxaire equipment, the York S1-7990-3591 is a critical OEM furnace limit switch designed for precision thermal monitoring. This auto reset limit switch is engineered with a snap-action contact system that opens at 180°F and automatically closes at 150°F, ensuring the HVAC blower motor and burners operate within safe operational parameters. As a genuine Source1 repair part, it offers exact physical and electrical compatibility with a wide range of mobile home furnaces and standard residential air handlers, including popular DGAM and DLAS series units. Replacing a tripped limit switch with this factory-spec component restores the safety sequence, preventing furnace short cycling or total system lockout caused by heat exchanger overheating. The L180F-30 thermal profile is specifically calibrated for high-limit protection, providing a reliable 12-24VAC/VDC interface that veteran contractors trust for preventing downstream damage to sensitive HVAC controls.

Key Benefits

• Precise Thermal Calibration: Features a factory-set 180°F opening point to protect the heat exchanger from excessive internal temperatures.
• Automatic Reset Logic: Eliminates manual resets by closing the circuit once temperatures drop to 150°F, maintaining consistent system uptime.
• Universal Source1 Fitment: Designed as a direct drop-in for York, Coleman, and Luxaire models, ensuring zero-clearance issues during installation.
• OEM Durability: Constructed to York technical specifications for better resistance to thermal fatigue compared to generic after-market switches.

Common Questions

What causes a York S1-7990-3591 to trip frequently?
Repeated tripping usually indicates restricted airflow, such as a clogged filter, blocked return vents, or a failing blower motor. If the switch remains open even after the system cools, the internal snap-disc may have failed.

Can I use this switch in a mobile home furnace?
Yes, this part is a standard high-limit safety for many Coleman and York mobile home furnace series (e.g., DGAM, DGAT) that require an L180F-30 rated control.

How do I test if this limit switch is faulty?
With power disconnected, use a multimeter to check for continuity across the terminals. At room temperature, this switch is "normally closed" and should show near-zero resistance.

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.