What does a high-limit switch do in an oil burning system?

In an oil burning system, the high-limit switch plays a crucial safety role by monitoring the temperature of the system. When the temperature exceeds a preset limit, the high-limit switch is designed to shut down the burner, preventing overheating and potential hazards such as equipment damage or fire. This automatic response is essential for maintaining a safe operating environment, ensuring that the system does not operate beyond its intended temperature thresholds. By shutting down the burner when necessary, the high-limit switch helps protect both the equipment and the surrounding area from potential risks associated with excessive heat. The other choices do not accurately describe the function of the high-limit switch, as it does not increase fuel flow, monitor combustion efficiency, or regulate oil pressure.