Which statement is accurate about conventional fan/limit controls?

Conventional fan/limit controls are designed to automatically regulate the operation of a heating or cooling system based on temperature. The correct response highlights that these controls are thermally driven, meaning they respond to temperature changes. When the temperature reaches a certain threshold, these controls activate the fan or limit action, promoting efficient temperature management within the system.

This thermally driven mechanism allows for precise operation; for instance, when the temperature in a furnace rises to a predetermined point, the limit control turns off the burner to prevent overheating. Conversely, when the temperature drops below a certain point, the fan control activates the blower to circulate air, contributing to both comfort and safety.

This understanding is fundamental for maintenance and troubleshooting in residential air conditioning systems, as it emphasizes the importance of temperature sensing in system operations. The other options do not capture this key characteristic of thermal response, making them less applicable in this context.