Plumbing Tips: The Toilet Flush Explained

Understanding how toilets work will help you anytime it is flushing wrong or not at all.

There are several different types of toilets, but the most common type is the "flush toilet". A flush toilet can be basically defined as "a toilet that eliminates its waste by a flow of water". The household flush toilet is usually just another working necessity in a house, and it's not thought about often... until it doesn't work right. Then, all you can think about is how to fix it to make it work right again. In order to be able to work on a flush toilet, and get it back to working order, you will need to understand how it works.

When you reach for the handle and pull it down, (flush the toilet), the handle - that is attached on the inside of the tank - to a lever, in turn, raises a rod or chain. When the rod or chain rises up, it lifts up a round part that is called a "flapper". The purpose of the flapper is twofold: it covers the round hole (the flush valve seat) in the bottom of the toilet tank to keep the water from flowing out of the tank. Its other purpose, when the toilet is flushed, is to rise up and allow a rush of water to be drawn from the toilet tank into the toilet bowl. The water rushes into the bowl through the hole in its middle, as well as from small holes that encircle the underside of the toilet bowl rim. Here's a tip for you: flappers are usually made of a pliable rubber, and they are available in many different sizes. If the flapper in your toilet bowl malfunctions, simply remove it from its hinges and replace it with a new, same - sized one.

After the toilet has been flushed and cleared of its waste, the toilet tank begins to fill up with water again. This water comes from a metal supply line that is piped in through the bottom of the tank. The supply line should have a shutoff valve placed in it so the water to the toilet can be shut off in case of an emergency. As the water is entering the tank from the supply line, it is split into two directions by an inlet valve. This inlet valve is most commonly known as a "ballcock." Most of the water is needed to fill the toilet tank, so the majority of it runs into there. The rest of the water runs into an overflow tube, and then, into the toilet bowl. Then, as water fills the toilet tank up, a floating ball that is attached to a lever to the ballcock, rises up as the water reaches it. When the tank is completely filled, the water pushes the floating ball up until it can't rise anymore. At this point, the level position of the floating ball causes the ballcock to shut the water off. Here is a helpful tip for you: there is a screw at the top of the ballcock that you can either tighten or loosen in order to adjust the level that the float reaches before it shuts off the valve.

Some toilets don't have a ballcock and an inlet valve set up. Instead, some toilets have a device that is known as a "float cup". The purpose of the float cup is the same as the ballcock/valve set up, but it works somewhat differently. The float cup actually moves up and down a tube as the level of the water goes up and down at the same time.

Here is another interesting tip: the water that is located inside the tank on your toilet is actually relatively clean. This is because it is filled up with clean water from the supply line. It is not filled with, or connected with, the water in the toilet bowl.

And, finally, if you ever need to drain the water out of your toilet bowl, like to replace the entire toilet, shut the water off at the valve in the supply line. Then, hold the handle down continuously and flush the toilet. Most of the water will be removed from the bowl. You can then suck out the remaining water by using a wet/dry vacuum.

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