How far must the vent terminal of a direct vent water heater with an input over 50,000 BTU be located from any opening?

The correct answer indicates that the vent terminal of a direct vent water heater with an input over 50,000 BTU must be located 12 inches from any opening. This requirement is primarily to ensure safety and proper venting. Adequate distance from openings such as windows, doors, or air intakes is essential to prevent the possibility of exhaust gases from re-entering the building.

In residential applications where high-efficiency water heaters are used, proper venting is crucial to maintain air quality and avoid health hazards associated with combustion gases. The specified distance allows for the safe dispersal of exhaust and minimizes the risk of backdrafts or obstruction caused by nearby openings, which could negatively affect the water heater's performance.

Other options present distances that do not meet the code requirements for venting in this context, thereby falling short in ensuring safe installation standards. Proper adherence to the 12-inch distance helps in compliance with local plumbing codes and national safety standards.