Fun Fact Friday: How toilets work

Toilet_370x580Do you know how a toilet works? Not everyone does! The typical toilet is made up of the commonly known parts like the flush lever, tank and the bowl, but also includes the flapper, flush valve, and overflow tube.

The toilet tank contains clean water, which is held in reserve for the next flush. When you pull the flush lever, the chain that’s attached (inside the tank) pulls up the flapper. The flapper is a rubber stopper on a hinge at the bottom of the tank, and when pulled, it releases the clean water into the bowl. The bowl itself works by gravity, so no mechanical parts are needed to initiate the actual flushing process. If you’ve ever emptied a mop bucket into a toilet, you probably noticed that the toilet “flushed itself”, with no need to pull the lever. It only takes a certain amount of water added to the bowl for it to empty itself, which is why the fresh water being released into the bowl initiates the flushing process.

The flow valve controls the flow of water back into the tank, and usually can be adjust to allow more or less water into the tank, as desired. The overflow tube is the tall plastic tube that sticks out of the water. This is there so that if the tank ever starts to overflow for any reason (such as a malfunctioning flow valve) the water can drain down the overflow tube and into the septic system, rather than out of the top of the tank.

Some other things to note:

  • If you ever suspect you have a leaking tank (which can cost hundreds in water bills) you can do a simple “dye test” by putting a few drops of food coloring into the tank when the toilet isn’t going to be flushed for a few hours (such as before going to work). When you return, if there is any dye in the bowl, then you know your tank is leaking. Naturally, the next flush is going to allow the dyed water into the bowl, which is why it’s important that nobody uses it while you’re doing the test. Small leaks can be corrected by rubbing petroleum jelly around the bottom of the flapper, which patches any small gaps in the waterproof seal, and then the dye test can be attempted again.
  • There’s a common “green” tip about placing a brick into the toilet tank to save water. This works by displacing the water and “fooling” the tank into allowing less water in. This tip does work, but you want to make sure that the toilet is pre-1995, as modern “low flush” toilets have only enough water to get the job done, and don’t work properly with less. Also, if you decided to do this, it’s better to use a full water bottle, rather than a brick, as the brick can break down over time and the sediment from it can cause other plumbing issues.

Want to learn more about toilets? Who doesn’t? Check out Stuff Happens with Bill Nye: Bathroom on Discovery Education Streaming!


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