Trane SWT1259 Limit Switch

The Trane SWT1259 Limit Switch is a critical furnace safety control designed to monitor high-limit temperatures within the heat exchanger. This OEM furnace limit switch features an auto reset mechanism with a fixed 190-degree trip point and a 160-degree reset point, ensuring precise thermal protection for residential and commercial gas furnaces. Engineered with a 3-inch insertion length, this bimetal disc thermostat (L190-30F) acts as a normally closed safety, breaking the 24V circuit to the gas valve if the plenum temperature exceeds safe operating parameters. Also identified as C340056P04 and SWT01259, this sensor is a direct replacement for failing high-limit controls in many Trane and American Standard air handlers. Reliability in the field is paramount, and utilizing genuine Trane parts ensures the internal bi-metal spring retains its calibration over repeated thermal cycles, preventing nuisance trips and protecting your customer's equipment from heat-related damage.

• Safe System Operation: Automatically interrupts combustion cycles to prevent heat exchanger fatigue and potential cracks.
• Precise Thermal Range: Features a 190°F open temperature (Cut-Out) and a 160°F close temperature (Cut-In) for consistent safety performance.
• Standard Insertion Depth: The 3" probe ensures accurate temperature sensing within the main supply air stream.
• Cross-Compatibility: SWT1259 is identical to C340056P04 and SWT01259, simplifying inventory management for service trucks.
• Reduced Service Calls: The automatic reset function restores operation once the unit cools, eliminating the need for manual intervention for temporary overheating events.

What fits models use the SWT1259? This part is commonly found in Trane XE80, TDD, and TUE furnace series, as well as various American Standard units utilizing a 3-inch limit probe.

Is the SWT1259 an automatic or manual reset switch? This is an automatic reset switch, meaning it will close the circuit once the plenum cools to 160°F without the need to press a reset button.

When should I replace my furnace high limit switch? If the furnace is short-cycling, the blower fan runs continuously despite no heat demand, or the switch shows no continuity at room temperature, it is likely time for a replacement.

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.