York S1-7705-3591 Limit Switch

The York S1-7705-3591 is a critical high-limit safety component engineered for precise thermal monitoring within residential and commercial gas furnaces. This Auto-Reset Limit Switch operates within a specific 125-145°F temperature range, serving as the primary defense against heat exchanger failure and overheating. Designed for seamless integration into York, Luxaire, and Coleman HVAC systems, this furnace high-limit replacement features a bimetallic disc that breaks the electrical circuit once the ceiling temperature is reached. In the field, technicians rely on the S1-7705-3591 to resolve common issues like rapid cycling or lockout codes caused by restricted airflow or failing blowers. The 125-145F AUTO Limit Switch utilizes a small-footprint flange for standard mounting, ensuring the sensor sits correctly in the airstream to provide accurate thermal feedback to the control board. Replacing a drifted or fouled switch with this OEM-spec part ensures the furnace operates within its designated safety parameters and maintains system reliable uptime.

• OEM Precision: Direct replacement for York, Coleman, and Luxaire part number S1-7705-3591.
• Automatic Reset: Automatically restores the circuit once the plenum temperature drops below the differential, reducing nuisance service calls.
• Safety Compliance: Maintains the integrity of the furnace safety loop by preventing burner operation during over-temp conditions.
• Durable Construction: Built to withstand the high-cycle thermal stress found in modern high-efficiency furnaces.

• What causes this limit switch to trip frequently? Usually, a trip is triggered by restricted return airflow, a clogged filter, or a failing blower motor, rather than a faulty switch.
• Is the S1-7705-3591 a universal part? While it fits many York-family units, always verify the specific temperature stamped on the existing switch to ensure the opening point matches 145°F.
• Does orientation matter during installation? Yes, the sensor must be positioned directly in the warmest part of the air discharge to respond accurately to temperature spikes.

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.