What is the primary purpose of a house drain?

The primary purpose of a house drain is to receive discharge from various drainage pipes. House drains serve as the main conduit for wastewater and gray water from different drainage fixtures within a home—such as sinks, bathtubs, and toilets—guiding this water toward the sewer system or a treatment point. This function is critical for maintaining a sanitary and functional plumbing system, ensuring that waste is efficiently transported away from the house.

While drinking water supply, venting, and hot water distribution are essential components of a plumbing system, they do not define the specific role of a house drain. The house drain is focused exclusively on the management and transportation of wastewater, making its purpose distinct and crucial in preventing backups and maintaining hygiene within the household system.