543-037

This 3-inch high limit switch is a vital safety component for residential gas furnaces and HVAC systems. Designed to monitor the internal temperature of the heat exchanger, this limit control acts as a safeguard against overheating. If the furnace reaches a temperature of 190°F, the switch automatically opens the electrical circuit to the gas valve, halting the heating process to prevent equipment damage and ensure home safety. Once the system cools down by 40°F, the switch automatically resets to allow for normal operation. Replacing a faulty high limit switch is essential for maintaining reliable performance and preventing frequent furnace cycling or total system lockout.
Type: HVAC High Limit Control Switch
Size: 3-inch
Dimensions: 3 inches
Application: Used in high-efficiency gas furnaces and central heating units to provide thermal overload protection and system safety monitoring.
Specifications: Open Temperature: 190°F; Close/Reset Differential: 40°F (Resets at 150°F); Circuit Configuration: Normally Closed (NC); Reset Type: Automatic.