Plumbing 101 – How Plumbing Works

You know that when you turn a tap, water comes out, and that depending on which tap you turn will determine whether your water is hot or cold. Sometimes water seems to move upwards, sometimes down, and sometimes to your frustration, not at all.

Here we’ll take a quick look at how these everyday systems work at their most basic level.

Plumbing has a long history beginning all the way back to ancient civilizations such as the Greeks, Romans, Persians, Indians and Chinese. It reached its apex in ancient Rome with the use of aqueducts and wastewater removal. After Rome’s collapse, water supply and sanitation didn’t improve for some time.

Anywhere a system has been used to convey fluids, the need for plumbing services has been right by its side. In other words, where water supply systems have existed, so have plumbers. The systems that exist today in your average Central Coast home did not just appear yesterday. They, like most technologies, have developed into incredibly streamlined and efficient systems that make living as we do possible.


The basics of plumbing are all based on simple laws of nature: gravity; pressure; water seeking its own level (the fact that if water is not disrupted by some other force, its surface will be level). This is the basis of every system or subsystem within plumbing: Cold and hot water tap supply; drain waste vent systems; sewage and septic systems, for example.

The system in your home consists of two subsystems: one brings freshwater in, and the other takes wastewater out. In other words, supply and drainage. These systems are entirely separate from one another.


The water that comes into your home comes in under high pressure – so that it can travel upstairs, around corners or wherever else you can imagine water going. This water coming in passes through a meter that registers the amount you use. The water pressure is at such a level that if a plumbing emergency like a burst pipe occurs, your home can get really wet, really quickly. It’s important to know where the main shutoff valve is (it’s usually right near the water meter), in the case of emergency plumbing!

Cold water is readily available from the main supply, however, to get that magical hot water coming out of your tap, it needs to take a little journey. This is where your hot water system comes in. Quite simply, a pipe carries cold water to the water heater, from there another line carries this hot water to all the fixtures that need hot water. A thermostat on the heater maintains your water at just the right level.


Whether you have a septic or sewer system, the principles of drainage are relatively the same. Unlike supply systems, which require pressure, drainage systems rely on a system of pipes that angle downward, letting gravity do her thing to take your waste to either a sewage treatment facility, or a septic tank.

This might sound simple on the surface, but in fact it is quite a complicated system – if it weren’t, maybe there wouldn’t be so many blocked drains in the world! Vent pipes and traps contribute to making this drainage process flow smoothly.

The vents that stick out from your roof allow air to enter the drain pipes. Without these, water would not flow properly at all (think of when air gets trapped underwater because it can’t escape and then reverse the idea).

“Traps” are those S-shaped sections of the pipes you see under your kitchen sink. Water flows with enough force to go through the trap and down to the drainpipe, but some water gathers in these traps. This is important because it forms a seal which prevents sewer gas from coming back into your home – a smell you likely don’t want next to your freshly picked flowers!


Like we said earlier, the supply and drainage subsystems are separate systems that make up one whole system. These don’t overlap, however, there are ‘bridges’ between the two: Plumbers call these fixtures.

A fixture is any device that draws freshwater and discharges wastewater, and they are all designed to keep the supply and drainage systems strictly segregated. So, toilets, sinks and washing machines, for example, are all fixtures, and a crucial part of what turns any plumbing system into a user friendly system within your home.

So, next time you turn on your tap, we hope you might be able to appreciate just how wonderful that hot water going down your drain really is!