The Major Components of a Residential Plumbing System

A residential plumbing system typically consists of the following major components:

Time to Read: 2 Minutes

Residential plumbing systems can be broken down into major categories based on functionality. The plumbing flat rate price book inside Flat Rate Plus Online, is organized by these categories. 

Water Supply: This includes the main water supply line, shutoff valves, and a pressure regulator.

Fixtures: These are the devices used to dispense water and remove wastewater, such as sinks, toilets, showers, bathtubs, and laundry facilities.

Drainage System: This includes the sewer main, branch drain lines, and vents.

Traps: These are U-shaped pipes located beneath fixtures that prevent sewer gases from entering the home.

Water Heater: This provides hot water for the home, and can be a tank-style or tankless model.

Sump Pump: This pump is installed in the basement or crawl space, and helps to prevent water damage by removing excess water from around the foundation.

Backflow Prevention Devices: These devices prevent contaminated water from flowing back into the main water supply.

Pipes: The pipes used in a residential plumbing system can be made of copper, PVC, or PEX, and are used to transport water and wastewater throughout the home.

Faucets and Valves: These devices control the flow of water to and from fixtures and appliances.

Septic Tank and Drain Field: If the home is not connected to a public sewer system, it may have its own septic system, consisting of a tank and a drain field that treats and disperses wastewater.

Why are Lavatory Repairs Separate from Other Plumbing Systems?

Lavatory (bathroom) systems are typically separated from kitchen, bar, and laundry systems. This is because the diameter of lavatory drain piping is generally 1.25″ where the others are 1.5″

About the Author, James R. Leichter

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James is a successful entrepreneur and master mechanic widely referred to as Mr. HVAC. His accomplishments include being the CEO and founder of Aptora, the President of RA Tax and Accounting, the founder of, and a partner with Pro-American Investments. He is also the creator of Flat Rate Plus®, which is hosted on this website.

James is well known for his burning passion to help contractors and it shows in his unique speaking style. His articles have been widely published by the industry’s most popular magazines. His videos have had over one million views. James has hosted management workshops all around the United States and has conducted onsite consulting with hundreds of contractors.