Which component must not be obstructed when ensuring accessibility for service and repair?

The component that must not be obstructed when ensuring accessibility for service and repair is the venting systems. Proper ventilation is essential in many mechanical systems, particularly those involving combustion or chemical reactions, to prevent the buildup of harmful gases or fumes. Obstructing venting systems can lead to dangerous conditions such as carbon monoxide poisoning, fire hazards, or system failures. Ensuring clear and unobstructed venting allows for safe and efficient operation of equipment, as well as easier access for maintenance and repairs.

Other components, while important, typically do not present the same level of risk or necessity for unobstructed access when compared to venting systems. Fuel lines, power sources, and insulation can often accommodate some level of obstruction or limited access, provided that they are still functional and compliant with safety standards. However, venting systems directly affect air quality and safety, making their accessibility critical in any mechanical setup.