NATE Gas Heating Practice Exam

The primary function of a furnace's high-limit control is to shut down the furnace when the temperature exceeds a safe limit. This safety mechanism is crucial in preventing overheating, which can lead to potential hazards, such as fires or damage to the furnace itself. The high-limit control monitors the temperature within the furnace and activates when it reaches a predetermined threshold. By doing so, it helps ensure that the heating system operates safely and efficiently, providing protection for both the equipment and the home. Overall, the high-limit control plays a critical role in maintaining safe operating conditions in a gas furnace.