How Plumbing Works: Everything You Need to Know About Pipes and Water Flow

By Benner Plumbing Staff | June 27, 2025

When it comes to home maintenance, few systems are as essential or as often overlooked as your plumbing. Every time you wash dishes, take a shower, do laundry, or flush a toilet, you’re relying on a complex network of pipes, valves, and fixtures to deliver clean water and carry away waste. While it might seem like magic, how plumbing works is actually based on straightforward principles. Understanding how it works can help you catch issues early, save money on repairs, and make smarter choices when upgrading or maintaining your home.

What Is a Plumbing System?

At its core, a residential plumbing system serves two main purposes:

  1. To deliver clean, potable water to your home’s fixtures and appliances

  2. To remove used or wastewater safely and efficiently

These tasks are managed by two separate but equally important systems:

  • The Water Supply System

  • The Drain-Waste-Vent (DWV) System

Let’s explore each system and how they function within your home.

1. The Water Supply System

This system is responsible for bringing fresh water into your home under pressure. The pressurized flow allows water to travel uphill, around corners, and to fixtures across different rooms. Here’s how the water supply system typically works:

  • Water Source: Homes either get water from a municipal supply (city water) or a private well system. In urban areas, municipal water is most common, while rural homes often rely on wells.

  • Main Shut-Off Valve: This valve controls the flow of water into your home. It’s essential for homeowners to know its location usually near where the main water line enters the home—because shutting it off is the first step in addressing any major leak.

  • Pipes: The water is transported via a network of pipes made from materials such as copper (durable and corrosion-resistant), PEX (flexible and easy to install), or PVC (affordable but not suitable for hot water). These pipes distribute water to sinks, bathtubs, toilets, washing machines, and dishwashers.

  • Fixtures: These are the visible points where you access water faucets, showerheads, toilets, and appliances.

Because this system operates under pressure, it can push water to any part of your home, regardless of gravity.

2. The Drain-Waste-Vent (DWV) System

Once water is used, it turns into waste and must be removed safely. The DWV system handles this task, relying not on pressure but on gravity and proper ventilation to move wastewater out of the house.

  • Drain Pipes: These pipes carry used water from sinks, toilets, and appliances to the main sewer line or septic tank.

  • Traps: These are the curved sections of pipe (often seen under sinks) that hold water to create a seal, preventing foul-smelling sewer gases from entering your home.

  • Vent Pipes: Ventilation is key to proper drainage. These pipes allow fresh air into the system, preventing vacuum pressure and helping water and waste flow smoothly. Without vents, drains would gurgle and flow inconsistently.

Eventually, all the drainpipes connect to a main sewer line, which directs waste away from your home to either a municipal sewage system or a private septic tank.

Common Plumbing Materials

Choosing the right materials can affect water pressure, safety, and long-term maintenance:

  • Copper: Strong, corrosion-resistant, and long-lasting—ideal for older homes.

  • PEX: A modern favorite for its flexibility, affordability, and easy installation.

  • PVC: Common in waste lines due to its low cost and ease of use, though not suitable for hot water.

Common Plumbing Issues to Watch For

Knowing how plumbing works means you can catch small problems before they become disasters. Keep an eye out for:

  • Low water pressure

  • Gurgling or bubbling noises in drains

  • Water stains or damp spots on walls and ceilings

  • Slow-draining sinks or tubs

  • Foul odors from drains or basements

Addressing these signs early can prevent mold growth, pipe damage, or major water leaks.

Why Plumbing Knowledge Matters

You don’t need to be a certified plumber to understand the basics. Here’s why learning about plumbing pays off:

  • Preventative Maintenance: Spot and address issues before they become expensive emergencies.

  • Improved Communication: Speak clearly and confidently with plumbers or contractors.

  • Smarter Renovations: Plan kitchen or bathroom upgrades with a clearer understanding of your home’s infrastructure.

Whether you’re tackling a DIY repair, planning a renovation, or just want peace of mind, having a grasp on how plumbing works is a valuable skill. And when the job is too big or complex, Benner Plumbing & Heating is here to help. With decades of experience and a commitment to excellent service, we’re your trusted partner for everything from leaks to full system installations.

Contact Benner Plumbing & Heating today to keep your home’s water flowing efficiently and reliably!

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