Arizona Plumbing Practice Exam 2026 – All-in-One Guide to Master Your Plumbing Certification!

To comply with plumbing codes for a new toilet, installing an air gap is essential. An air gap is a physical separation between a water supply outlet and a flood level rim of a fixture, such as a toilet. This installation is critical in preventing backflow contamination of the drinking water supply.

By maintaining this separation, the design ensures that if a toilet overflows or there is a pressure drop in the system, contaminated water cannot siphon back into the clean water supply. This is particularly important given the potential for waste and other non-potable substances present in the toilet.

In contrast, while tankless heaters, backflow preventers, and vent pipes serve important roles in plumbing systems, they do not specifically address the need to protect against the risk of contamination linked to the installation of a toilet. Tankless heaters are related to water heating, backflow preventers are used in various applications to prevent reverse flow but are not a requirement specifically for toilets, and vent pipes are primarily for allowing air circulation to prevent vacuum conditions in drainage systems rather than providing health protection against wastewater. Hence, the air gap is the critical component listed that aligns directly with plumbing codes concerning toilet installations.