543-190

This premium 3-inch high limit switch is a vital safety component for residential and commercial heating systems. Designed to monitor the heat exchanger temperature within a furnace or HVAC unit, this thermal cutout switch acts as a critical fail-safe. If the internal temperature reaches a level that could cause damage or pose a safety risk, the switch automatically interrupts the electrical circuit to shut down the heating element or burner. Featuring an L190-40F calibration, it is engineered to trip at 190 degrees Fahrenheit and reset once the temperature has cooled by 40 degrees. Replacing a faulty or tripped limit control is essential for restoring furnace operation and ensuring the long-term reliability of your heating equipment.
Type: High Limit Control Switch
Size: 3-inch probe
Dimensions: 3 inches (insertion depth)
Application: Used in gas-fired furnaces, electric heating systems, and HVAC air handlers as a primary safety thermal cutout.
Specifications: Opens at 190°F (88°C); Closes at 150°F (66°C); 40°F differential; 3-inch insertion length for accurate temperature sensing within the plenum or heat exchanger.