543-003

This premium 3-inch high limit switch is a critical safety component designed for forced-air heating systems and residential furnaces. Functioning as a thermal cutout, this switch monitors the internal temperature of the heat exchanger or plenum. If the system exceeds a safe operating temperature, the switch automatically breaks the electrical circuit to prevent overheating and potential damage to the appliance. Once the temperature cools to a safe level, the internal bimetal disc resets, allowing the system to resume normal operation. Essential for DIY furnace repair and HVAC maintenance, this high-limit control ensures your heating equipment operates within manufacturer safety parameters, protecting your home from fire hazards and mechanical failure caused by restricted airflow or component malfunction.
Type: High Limit Safety Switch
Size: 3-inch insertion depth
Dimensions: 3 in
Application: Commonly used in gas and electric furnaces, air handlers, and forced-air heating systems to monitor plenum temperature and provide high-heat protection.
Specifications: Standard 220-degree Fahrenheit cutout (L220) with a 30-degree Fahrenheit differential (30F) for automatic reset.