543-011

This premium 3-inch high limit switch is an essential safety component for residential furnaces and HVAC heating systems. Designed to monitor internal air temperatures, this thermal limit control acts as a critical fail-safe by automatically breaking the electrical circuit if the furnace heat exchanger reaches an unsafe temperature. Specifically calibrated to open at 135°F and reset once the temperature drops by 30°F, it prevents overheating, protects the heat exchanger from damage, and ensures the safe operation of your heating equipment. If your furnace blower runs continuously or the heating cycle cuts out prematurely, replacing a faulty high limit sensor is a common and necessary repair for maintaining home safety and system efficiency.
Type: High Limit Control Switch
Size: 3-inch probe
Dimensions: 3 in
Application: Commonly used in forced-air furnaces, HVAC blower assemblies, and heating units as a safety cutout to prevent equipment overheating.
Specifications: Temperature Rating: Open at 135°F, Close at 105°F (30°F Differential); Mounting: Flange mount; Sensor type: Bimetal disc.