Final answer:
A line-duty overload detecting an overload in a heater's electrical circuit will interrupt the power flow to prevent damage and danger.
Step-by-step explanation:
When a line-duty overload protecting a heater detects an overload, it is designed to interrupt the electrical circuit to prevent damage to the heater due to excess current. Usually, overload protectors achieve this by either tripping a circuit breaker or blowing a fuse. This is an essential safety feature that helps prevent potential dangers such as fires or equipment failure. The interruption stops the flow of electricity until the problem causing the overload can be resolved, such as a malfunctioning component, short circuit, or a current demand that exceeds the system's capacity.