What is the primary purpose of a trap primer in plumbing systems?

The primary purpose of a trap primer is to maintain water in a trap, which is essential for preventing sewer gases from entering a building. Traps are designed to hold a certain amount of water, creating a barrier that blocks odors and gases from the sewer system. When water evaporates from the trap due to inactivity—such as in seldom-used sinks or floor drains—the trap becomes ineffective, allowing foul gases to escape into the living space.

A trap primer automatically adds a small amount of water to the trap as needed, ensuring that the water seal is always intact. This functionality not only enhances the building's hygiene and comfort but also contributes to using plumbing systems in compliance with health and safety regulations.

Other options, while relevant to the plumbing context, do not define the primary function of a trap primer. Increasing water pressure relates to other plumbing aspects, aiding in waste disposal is more about the overall plumbing system rather than a specific function of a primer, and enhancing plumbing aesthetics does not relate to the operational purpose of a trap primer at all.