True or False: Forced draft systems that operate under positive pressure must be gas tight.

Forced draft systems that operate under positive pressure are indeed required to be gas tight. This requirement ensures that any combustion gases or byproducts generated during operation do not leak into the surrounding environment, which is crucial for safety and compliance with building codes. A gas-tight system helps protect occupants and the environment from harmful emissions, including carbon monoxide and other hazardous gases.

In a forced draft system, air is pushed into the combustion chamber, which creates a positive pressure. If there are leaks in the system, it can allow dangerous gases to escape, leading to potentially hazardous conditions. Therefore, maintaining the integrity of the system through gas-tight construction is a fundamental aspect of ensuring safe operation and preventing leaks that could endanger health and safety.

The other choices do not accurately reflect the necessary safety measures needed for forced draft systems operating under positive pressure. Having gas-tight construction is a universal requirement, regardless of the location or operational status of the system.