What component is installed inside the furnace plenum to sense air temperature and control furnace operation?

The component that is installed inside the furnace plenum to sense air temperature and control furnace operation is the fan and limit switch. This device plays a crucial role in the efficient operation of a furnace by monitoring the temperature of the air within the plenum. When the air temperature reaches a specific threshold, the fan and limit switch activates or deactivates the blower motor accordingly.

This ensures that the air being circulated by the furnace is neither too hot, which could damage the system or create unsafe conditions, nor too cold, which would prevent adequate heating of the home. The fan and limit switch is vital for maintaining safe operating conditions within the furnace, helping to prevent overheating and ensuring the system operates within its designed parameters. Additionally, this component interacts with the thermostat, but it is specifically designed to function within the plenum, providing direct feedback on the air temperature.