Mechanical draft systems must be what?

Mechanical draft systems must be listed, meaning they must comply with specific safety and performance standards established by recognized testing organizations. This ensures that the systems have been evaluated for reliability, efficiency, and safety in a variety of operational scenarios. When a mechanical draft system is listed, it indicates that it meets the standards required for installation and use, which helps ensure that it operates correctly and minimizes risks such as improper venting of combustion gases.

The requirement for a listed status is particularly important in contexts such as building codes and insurance mandates, where adherence to safety standards is crucial. This ensures that the installed systems are not only effective but also safe for users and compliant with legal regulations.

Being adjustable, removable, or generic might refer to features that can be beneficial in certain circumstances, but they do not carry the same crucial significance for safety and reliability as being properly listed.