Plumbing 101: How a Toilet Flushes

Ever wondered how a toilet flushes? Understanding one of the most common appliances in your home – the toilet – is actually a lot more complicated than you might think.

One Call Plumbing is your local plumbing expert. We’ve worked on thousands of toilets over the years, and we’re fully versed in the intricacies of plungers, flushing mechanisms, and valves.

Here’s a comprehensive guide to the way a toilet flushes.


Part 1: The Basics

The flushing mechanism on any toilet owes its functionality to several important parts:

  • Chain
  • Flapper
  • Float Ball
  • Refill Tube
  • Handle
  • Flush Valve/Chain

All of these parts live in the tank of the toilet, which is the rectangular part in the back. Toilets flush thanks to gravity.


Part 2: Washout

When the flushing handle is depressed, the flush valve chain is raised, in turn raising the valve itself, which sits on the bottom of the tank. The valve separates the tank from the bowl, so all at once the water in the tank (around two gallons) rushes into the toilet bowl.


Part 3: Siphoning

Once the toilet bowl is full of tank water, the water is siphoned through a long, curved pipe behind the toilet into the sewer system. This process works because as you flush, the extra water in the bowl causes the siphon tube to fill, emptying all the water into the sewer. This action results in a change of pressure which causes the tell-tale “gurgling” noise you hear as your bowl empties out.


Part 4: Refill

Once all the water is emptied from the tank, the float ball inside it drops due to gravity. This, in turn, opens the supply line valve to allow more water to refill the tank; once enough water has filled the talk to lift the float ball back to its original position, the refill process is complete.

If any one of these components malfunctions, the toilet may cease to flush the way it’s supposed to. The valve chain could be unhooked or the lift arm may be bent or broken. Components wear out over time, and valves may stop sealing or float balls may become punctured.

If your toilet isn’t flushing the way you expect it to, you need the help of an experienced plumber. One Call Plumbing is Charlotte’s choice for fast, reliable plumbing services and we’ve got decades of experience handling everything from busted pipes to leaky commodes.


If your toilet is running, flushing incorrectly, or not flushing at all, don’t wait.
Contact your friends at One Call Plumbing today to schedule your appointment right away. You deserve a toilet that works!