Trane SWT04156 L110-20F Furnace High Limit Switch

Description

Trane SWT04156 L110-20F Limit Switch Overview

The Trane SWT04156 is an OEM replacement high limit switch designed to protect Trane heating systems from overheating conditions. Designated as an L110-20F model, this limit switch is engineered to open the circuit at 110°F and features a 20°F differential, allowing the switch to automatically reset once the temperature drops back to a safe operating level. Reliable overheat protection is critical to the safe and efficient operation of any forced-air furnace, and this genuine Trane component ensures your system performs to factory specifications.

Key Features

• OEM Trane replacement limit switch — SKU SWT04156
• L110-20F designation: opens at 110°F, 20°F differential (resets at 90°F)
• Automatic reset operation for convenient, reliable protection
• Designed to interrupt the heating circuit upon detecting unsafe temperature levels
• Engineered for direct OEM fit in compatible Trane furnace and air handler applications
• Helps prevent heat exchanger damage and potential fire hazards caused by overheating

How It Works

The limit switch continuously monitors the temperature within the furnace heat exchanger or plenum area. If the temperature rises to 110°F — indicating a potential airflow restriction, blower failure, or other unsafe condition — the switch opens, cutting power to the burner or heating element. Once the system cools and the temperature falls by 20°F (to 90°F), the switch automatically resets, restoring normal operation. This automatic reset functionality minimizes downtime while maintaining a critical layer of safety.

Application

• Compatible with select Trane and American Standard furnaces and air handlers
• Ideal for HVAC technicians performing OEM-spec repairs and maintenance
• Recommended for use when the original limit switch has failed open, failed closed, or is showing signs of wear

Why Choose OEM Trane Parts?

Using genuine Trane replacement components like the SWT04156 ensures proper fit, function, and longevity. OEM parts are manufactured to the same tolerances as the original equipment, helping to maintain system warranties and deliver dependable performance season after season.