Goodman Rollout Switch

A furnace limit switch (also called a high limit switch or fan limit switch) is a safety and control device that monitors the air temperature inside the furnace. It ensures the furnace operates safely by: Turning the blower fan on and off at the right temperatures. Shutting off the burners if the furnace overheats. Essentially, it prevents damage to the furnace and protects against fire hazards caused by excessive heat.