A Mini Guide to Help You Understand the Plumbing Basics of Your Home


Whether you have a small or large home, the plumbing system works on the same basic concepts. This can seem very complex and confusing if you’re looking at a diagram on a blueprint. However, once you learn the basics of residential plumbing, it’s pretty straightforward. Understanding your plumbing gives you an advantage when dealing with plumbers or trying to diagnose issues that you can fix yourself.

We put together this guide of how your plumbing works so that you can have a knowledgeable conversation when you interview plumbers for upgrades or repairs.

Main Parts of a Residential Plumbing System

The two main parts of your homes plumbing system include the water supply system that furnishes clean water to the home and the wastewater system that drains water that’s been used. After reading this article you’ll be able to navigate your home’s plumbing system when discussing plumbing issues. When you talk to a professional, you’ll understand the lingo and be able to make a clear decision.

Let’s take a look at these two main systems more closely, starting with the water intake supply system period.

Water Intake Supply System

The water intake supply system circulates water coming off the main valve from the city water supply. The source is probably buried beneath the street in front of your home. The incoming water is maintained under high pressure to allow it to flow to all the parts of your home. This is how you get fresh clean water for bathing, cooking and other needs.

For homes that use municipal water, freshwater comes into the property through the main. This is typically a large pipe running parallel to the street. However, some homes use well water. If this is the case in your home, you probably use a pump to increase the pressure of the water that comes out of your shower and faucets.

A shutoff valve can typically be found before and after your water meter. This setup allows you to shut down the incoming freshwater so that you or your plumber can work on the plumbing.

The water intake system is a crucial component of your home plumbing. Without it running water would never make it to the toilet, shower, or sink.

A dedicated pipe supplies the water heater with fresh water. Recently, tankless water heaters have become powerful enough to use in the new construction of single-family homes. Previously, these compact systems were used mainly in apartments and small condos.

If you have clean, instant hot and cold water throughout your home, the water intake system is doing its job and operating effectively. If you spot a problem, knowing the terminology can make the conversation with your plumber more productive.

Drain Wastewater System

The drain wastewater system removes used water from your home and empties it into the municipal sewer system. Some homes may have a septic tank that holds wastewater, requiring occasional pumping to empty it.

Water pressure fuels the water intake system. Meanwhile, gravity is used to drain wastewater away from the home. Drainage pipes angle downward so that gravity can transport the gray water out of your house. The wastewater system is more complicated than the intake pipes.

The drainage system includes traps, vents, and other features that help gravity move the water along. A quick glance at the roof reveals vent pipes coming out of most homes above the shingles. A “trap” looks like a P turned on its side and one lies under each sink in the home.

If you drop something down the drain, the trap prevents it from washing away in the pipe. This is good news if your wedding band or other jewelry falls down the drain, it won’t go very far.

Supply and Drainage Subsystems

The supply and drainage subsystems are separate functions. Although, there bridges between the two, known as fixtures. These are the working ends of the plumbing system that make it such a modern convenience.

Tubs, sinks, and toilets are examples of fixtures. Additionally, your outside faucet is also considered a fixture and so is the connection to the washing machine. Any devices that draw and eliminate wastewater are also fixtures; they keep the supply and drainage systems separate.

Many fixtures have their own shutoff valves, which is convenient if you don’t want to shut off the main water supply. Quiz your family on the location and operation of this valve in case of an emergency or to prevent flood damage in your home.

When to Turn Off the Water

Before completing plumbing projects and repairs, turn off the fixtures’ water supply. You can also shut off the main valve if you can’t find or turn off the appliance-specific shutoff valve.

Once the wastewater leaves the home, it typically empties into your septic tank or the community sewer.

Wastewater drain systems have a cleanout plug. They are designed to make it easy to remove waste material before it can clog the pipe.

Have you ever wondered why the waste drains are larger than the intake pipes that bring fresh water to your home? The larger size makes it easier for them to carry away the associated materials.

Keep in mind that older homes have fewer shutoff valves than modern ones, making maintenance a bit tricky.


You should now be familiar with the main two components involved in residential plumbing systems. There’s nothing much worse than waiting for a plumber to fix a used toilet. You may need new fixtures, pipe replacement and repair, or other plumbing services.

Put that to good use when you set up an appointment or call bluefrog Plumbing + Drain services. Ask us any questions you have regarding clogs and other plumbing problems.

Photo By Dmytro Zinkevych at Shutterstock

Call Now For Emergency Service!

Find A bluefrog Plumber Near You
plumbing company

bfpd Proactive Protection ProgramTM


  • Priority Service
  • Free Annual Plumbing Evaluation
  • 15% OFF Service