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Toilet Anatomy: Knowing the Parts of a Toilet

iliaaailetFixing a toilet can be intimidating when you don’t know the parts of a toilet. So, it is important to know what they are and what they do before you start tinkering with them. This article will tell you everything you need to know about these various parts of your toilet, so you’re better informed before starting any work on it.


How does a toilet work?

Here’s the rundown of how a toilet works: when the handle is pressed down, it is connected to a chain that lifts up the flapper inside of the tank. Then, the water flows inside the tank, goes down through the flush valve into the bowl, and fills it. The water then goes through the trap, into the main drain, and passes out of the house into the sewer or septic system.

Once the toilet tank is empty, the flapper closes and forms a seal. The fill valve turns on, and new water fills back up in the tank. The water comes in through the base of the valve and through the refill tube to the overflow tube. When the water rises in the tank, the float rises with it and tells the water supply line to stop until the next flush.


Toilet parts and how they work

There are two main parts to consider: the toilet tank and the bowl. Let’s look at the different ones in detail to see how a toilet works.


Toilet tank parts

Toilet tank and lid

toilet tank

The tank is a porcelain toilet bowl attached to the top of the bowl, which holds the freshwater. It contains water from the water supply. When flushed, it transfers this clean water into the toilet bowl to flush the contents of the bowl down the drain.

The tank lid is made of the same material as the tank and sits on top to keep out debris and to prevent water from splashing out.


Toilet flush handle and flush rod

Toilet flush handle and flush rod

The toilet flush handle attaches to a lever with a chain that lifts up the flapper inside of the tank. So when you push down on the toilet handle, it is connected to this chain and lifts up the rubber stopper so that the water in the tank can pass to the toilet bowl.


Lift chain

Toilet Handle Chain Stainless Steel Toilet Flapper Lift Chain Replacement Fits Most Toilet Flappers (3)

This chain connects the flush rod to the flapper, made of plastic or metal. It’s called the lift chain because it lifts the flapper valve.

It’s essential that it is adjusted properly as it’s how the toilet works. If not, the flapper won’t close (too short), or the chain can get stuck (too long) between the flapper and the flush valve, leaving water constantly flowing into the bowl. These chains are easy to replace and swap out when needed.


Toilet float ball or toilet float cup

Toilet float ball

There are two types of ball floats. One is a tank ball float that floats up with the water level in the tank. It is connected by a metal bar.

ball floats

The other type of float is made of plastic and floats, but it has two levers that open or close the fill valve when water flows into the tank.


Flush valves/ Tank O-Ring Seal

Flush valves

Flush valves let water flow from the supply line into the tank. A rubber O-ring, also called the flush valve seat helps ensure no water spills out of the tank and onto the floor.

The tank O-Ring Seal is a rubber ring that sits on the tank’s base. The flush valve seat also ensures a proper seal between the bowl and the tank. The seal needs to be replaced periodically as it can crack and break with age.


Toilet Fill Valve

Toilet Fill Valve The toilet fill valves (also knowns as ballcocks) are where the water comes into the toilet tank from the supply line. There is a float on the fill valve, and as the water in the tank rises, so does the float. Once the float reaches a certain level, it cuts off the water, and stops filling with excess water. This also houses the trip lever and the float valve.




The toilet flapper is the lid that covers the hole in the tank and sits on top of the flush valve. It is often made of rubber as a rubber flapper but can also be made of metal or plastic.

A rubber flapper can become warped, and mineral deposits build-up, so it’s essential to clean them regularly. It is also possible for them to crack with age – if this happens, they should be replaced.


Overflow Pipe

Overflow Pipe

The overflow pipe is found in the middle of the tank. It is designed to keep the water level inside the tank at a height that will not exceed the height of the overflow pipe. This prevents the tank from overfilling with water should there be an issue with the fill valve or float.

When you hear a running toilet, the water hasn’t turned off and is running into it via the overflow tube. This is either a fill valve issue or a flapper issue. 


Toilet bowl parts

The bowl is the place where the waste goes and is usually made out of porcelain. This is where the waste collects and passes through into the septic system or sewer. There are two main types of toilet bowl shapes: elongated and round. You can read about the differences between elongated vs. round toilets here.


Wax Ring

Wax Ring

A wax ring is a rubber disk located on top of the pipe leading from the toilet to the base of the bowl. The vertical side of the tube then sticks into a hole in the bottom of the bowl.

The purpose of a wax ring is to seal any gaps between the toilet and floor and to provide a cushion for pressure.

It is on the toilet flange to close gaps and prevent leaks as water passes from the bowl to the pipes. When this starts, you will see the water leak out from the base by the tank bolts (this is the same for one-piece and two-piece toilets). They are simple to replace but can be tricky as you need to remove the whole thing.


Floor flange

toilet Floor flange

The floor flange is a circular piece attached to the base of the toilet and then stuck onto the floor pipe. The purpose of this part is to hold up your toilet and support its weight.


Floor flange seal

Floor flange seal

This ring is screwed around the opening of the waste pipe, creating a watertight seal between it and your floor where it meets. 


Shut off valve

Toilet Shut off valve

The shut-off valve is outside of your toilet. The on-and-off switch for your freshwater supply line runs into the tank after every flush. 

It’s good to check this the next time you flush the toilet because old ones may not have a handle on them to turn on or off. This can be an issue when it starts leaking water from the bottom of the toilet or the rubber washers start to crack, and you need to know how to turn the water off.


Final thoughts on toilet bowl parts

Now that you know all the parts of your toilet and how it works, it should be easier to know what to do when it is broken. Most two-piece toilets are straightforward to repair, and there are several instances when you can DIY.

Things like water constantly flowing or replacing the flush valve gasket are simple to do when you know what these parts are and what they do. Check out our toilet repairs and tips below. 


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