How does a hi-metal fan switch operate the blower motor on a gas furnace?

A hi-metal fan switch is designed to control the operation of a blower motor in a gas furnace based on temperature changes. The correct choice emphasizes that the fan switch activates the blower motor when a specific temperature threshold is reached, and then it turns off the motor once that threshold is exceeded or not maintained. This ensures that the blower operates effectively to help distribute heated air throughout the space as needed, engaging when the furnace produces heat and disengaging when it is no longer necessary.

This operation is essential for maintaining consistent temperatures and energy efficiency, as it prevents the blower from running unnecessarily when the furnace is not heating. Understanding how this switch reacts to temperature changes is critical for troubleshooting and ensuring the optimal performance of the heating system.