543-018

This 3-inch High Limit Switch is a critical safety component designed for modern HVAC systems and forced-air furnaces. Its primary function is to monitor the internal temperature of the heat exchanger or plenum, automatically cutting power to the heating source if temperatures exceed a safe operating threshold. Featuring a precision L190-30F thermal profile, the switch is engineered to open the circuit at 190 degrees Fahrenheit and reset once the temperature drops by 30 degrees. Replacing a malfunctioning or tripped high limit control is essential for preventing system overheating, protecting the heat exchanger from damage, and ensuring the safety of your home heating system. This durable, snap-action thermal sensor is a standard requirement for maintaining proper airflow and temperature regulation in residential and commercial heating units.
Type: HVAC High Limit Control Switch
Size: 3-inch insertion depth
Dimensions: 3 in
Application: Forced-air furnaces, central heating systems, and HVAC air handlers designed to prevent system overheating.
Specifications: Opening Temperature: 190°F; Temperature Differential: 30°F; Switch Type: Normally Closed (NC); Reset Type: Automatic.