How a Toilet Works

How a Toilet Works

The toilet is referred to by several nicknames – lavatory, loo, outhouse, privy, latrine, the Gents, the Ladies – but irrespective of what you choose to call it; it is, in fact, one of the most important places in any residence – homes, offices, restaurants, etc. It is nearly impossible to imagine a functioning building without a minimum of one toilet on every floor. 

Except you are a plumber, chances are, you do not exactly know how a toilet works. If you are inquisitive or just curious to know how a toilet works, you have visited the right place. This blog is rich with information that will walk you through the inner workings of a toilet. However, before learning how a toilet works, a few things – such as the types and parts of a toilet – will make it easier to understand. 


What Makes up a Toilet?

For starters, flush toilets consist of two primary parts; the tank and the bowl. The toilet tank is placed at the top back of the toilet bowl, against the wall, like the back of a chair. It has a flush handle and a lid. The tank features a flapper, overflow tube, and fill valve. On the other hand, the bowl is positioned beneath the tank. It drains out into the siphon. It features a toilet seat.

There are a few requirements toilets materials should cover. They must be :

  • Solid
  • Hygienic
  • Water resistant
  • Chemical resistant
  • Easy to maintain and clean
  • Must not be sensitive to changes in temperature

Although most of them are made from porcelain, others are made from stainless steel. There are several toilet styles, types, and flushing mechanisms to pick from. Knowing the different types of toilets will help you better understand how they work. Below, we have discussed the types of toilets in detail.

Types of Toilets

Toilets have advanced over the years across various continents. Today, toilet designs continue to advance as technology improves and people demand a larger range of functionality and features. Below are the various types of toilets, representing striking and widely used designs around the world.  

1. Flush Toilet

Empty Toilet Bowl - Flush

The flush toilet is the trendiest and most commonly used toilet today. They are found in most traditional homes, commercial places, and office buildings. His type of toilet consists of a seat, bowl, tank, lid, and a siphon tube that leads to a drainage system.

This type of toilet has a siphon having an inverted U-shape function to keep the water level in the toilet bowl consistent – this is one of the most functional engineering designs. In addition to mitigating odor and germs, the water in the bowl also seals up sewer gas from the drainage pipe into the house. Most flush toilets drain into septic tanks or neighborhood sewers.

This type of toilet – flush toilets – can use up to twenty-seven percent of house water consumption. However, some of the latest models are built to use less water. For example, toilets with fewer flush levels reduce the water used daily.

The dual flush mechanism is also designed in a way that reduces the consumption of water, thus allowing you to choose between the hard and liquid-waste flush. In most establishments, less water is used by reusing water from appliances such as washing machines and dishwashers – this type of water is known as gray water.

Most of the flush toilets in the market today are made of porcelain. Porcelain consists of a water and clay mixture burnt at very high temperatures. Although a major part of the clay used is of kaolinite origin, other minerals such as steatite, feldspar, quartz, feldspar, and alabaster are also sometimes part of the porcelain makeup.  

2. Vault Toilet

vault toilet

This type of toilet is a flush-free unit that is buried underground. Here, hard waste is stored in it and eventually plumbed out. But as for liquid waste, they are drained into the soil. This type of toilet is commonly placed in a small privy.

3. Pit Toilet 

pit toilet

A pit toilet is also known as a pit latrine. This type of loo is a rough-and-ready, outdoor toilet that usually ranges from a squatting pan to a dugout in the soil. This type of toilet is trendy in rural settings and developing countries.

In most cases, this type of toilet is usually built for emergency relief. For example, army troops will usually use pit latrines when deployed in places that are removed from regular plumbing systems. For sanitation, pit latrines need to be placed far from streams that supply clean water, especially drinking water. 

Before the Second World War, pits were usually ill-placed in warzones. And this led to diseases that killed more soldiers than those that died from tanks, guns, and bombs.

4. Chemical Toilet

chemical toilet

Chemical toilets are common in passenger vehicles such as trains and airplanes. Chemical solutions are used in this type of toilet in lieu of water which is usually due to the lack of running water supply.

5. Dry Toilet

dry toilet

Dry toilet is so-called because it doesn’t need water supply to get rid of waste. This type of toilet come in quite a few designs highlighted as follows;

* Incinerating toilet – wastes are burnt

* Composting toilet – wastes are decomposed by the addition of carbon elements

* Freezing toilet- wastes are frozen

* Tree bog – here, solid wastes are turned into fertilizer

* Pit latrine – wastes are passed into a hole in the ground.

6. Portable Toilet

Portable Toilet

Portable toilets are also known as porta pots. They are unisex facilities, single-unit that are commonly seen at county fair, construction sites, and other outdoor events in remote locations. Porta pots are so-called because they can easily be transported through truck and set up momentarily at various locations when needed.

This type of toilet consists of a plastic toilet, a lockable door, and waste receptacle. They flush with chemical disinfectants. The receptacles are emptied every day and washed regularly.

7. Flying Toilet

flying toilet

You may be wondering how this type of toilet work. It is basically in a bag; thus, you do not even need a tank. This toilet is, in fact, not a toilet. It is a practice in some parts of the world where people excrete into plastic bags and then toss them very far away.

This practice has, however, led to sanitation issues. This is due to the littered plastic and human waste in some rural parts of the continent. Due to these reasons, the types of bags that have birthed this phenomenon are now banned in Uganda, Tanzania, and Kenya.  

8. Floating Toilet

Floating Toilet

This type of toilet is for people living in small spaces. It is an alternative to grounded toilets. It is often also used in places that typically lack plumbing and are vulnerable to flooding. This type of toilet stores human waste in a tank that is later removed. Some flying toilets divert liquid waste into separate systems.

9. High-Tech Toilet

High-Tech Toilet

High-tech toilets are often found in financially well off and tech-savvy homeowners. These people have the option of using toilets that provide tons of advanced features which include bottom washers and dryers, auto-flush, deodorizers, noise concealers, seat heaters, and automatic seat-sheet replacement. A few of the most high-tech models on today’s market offer basic health reports that are based on analysis of human bodily waste.

Flush Toilets 

For the sake of emphasis, we shall focus on flush toilets. At first sight, toilets seem pretty simple; all you see is a simple-looking bowl, a square-shaped tank behind the seat called a cistern, and a waste pipe going through the floor, waiting to carry away your bodily waste. All you need do is pull the handle by the side of the tank or push the button, and it does the rest. 

Most flush toilets are majorly mechanical. You turn the handle which pulls the chain, and the tank empties via the force of gravity. They flush your bowl clean and refill the tank with the help of levers inside. And levers are a perfect example of what scientists call a simple machine. This might seem quite simple. However, there is more to flush toilets than this. 

When you pull the handle, the tank has to refill on its own from a sort of faucet on the side, and the refilling operation must last long enough to fill the cistern to a level without causing it to overflow. The bowl you sit on is even more technical and sophisticated than it looks too. 

You may have noticed that your toilet bowl always has a small quantity of water in its bottom – it never empties completely. You see this water because some water is always trapped in the S-trap or S-bend. This is a large rounded pipe at the base of the toilet. This small amount of water you see helps to seal off the sewage pipe at the bottom, thus stopping bad smells and germs from getting up into your bathroom.

The S-trap also means that the pipe from the toilet bends upward before bending back down again. Due to this, when water flows from the cistern into the toilet bowl and drains out via the pipe, it has sufficient momentum to create a sucking effect (siphon), whose function is to empty the content in the bowl.  

The Parts of a Flush Toilet

To better understand how a flush toilet works, it is essential to learn about its part. Below, we have highlighted the parts of a flush toilet. Be sure to learn these parts, as it will help you understand how a toilet works.

1. Refill Tube

The toilet refill tube is a plastic tube in the middle of the toilet tank. Its role is to dribble water into the toilet bowl when it is refilling. Toilet bowls must have a small quantity of water sitting at the bottom as a trap that covers the bathroom against sewer gases.

It is essential to note that plastic refill tubes may crack, causing it to leak over time. The solution is to buy a refill tube repair kit and install it in place of the broken one.

2. Flapper

The flapper is a plastic stopper found on the inner base of the toilet tank. It sends water into the toilet bowl by lifting and closing. The toilet lever controls the flapper through the chain. After the water has been allowed to flow, the flapper falls back in place and closes the hole at the base of the tank, similar to a rubber stopper in a kitchen sink or a bathtub.

Toilet flappers can become hard over time and lose its seal. This is usually a common culprit for leaking toilets. Thankfully, new flappers can be bought independently and mounted on one-on-one basis. They sometimes is a part of refill repair kit for toilets, which includ related hardware, toilet fill valve, and the flapper.

3. Chain

Toilet chains are sometimes called lift chains. They are short strips of metal-linked chains that connects the toilet flapper to the toilet lever. After the lever is submerged, it drags the chain, which in turn raises the toilet flapper.

Because of the amount of usage toilet chains go through, they usually break. If the chain breaks and detaches at either end, you can be a new chain and install it, or reattach it using a small piece of wire. Toilet chains come as part of a toilet refill repair kit or a flapper kit.

4. Handle

The toilet handle is situated on the toilet tank that is used to flush the toilet. In most modern flush toilets, the handle is a large button located on the top of the tank lid. Dual flush toilets have this button divided into two: the smaller one for flushing liquid waste while the larger one for flushing solid waste.

The handle is attached to a long arm that is extended into the tank. The end of the handle pulls the chain that releases the toilet flapper. 

It isn’t common to have a faulty toilet handle, but the arm inside the tank can break or bend from repeated use. You can bend metal arms to straighten them again. Broken or bend plastic arms must be replaced. The ram and the handle are one piece, so you must replace them together when one or both are faulty.

5. Float

The float is an aluminum ball or a round plastic ball that is light enough to float on top of water in the tank. The float is responsible for managing the water level in the tank.

When flush toilet floats no longer float on the water, the most ideal solution is to install a new float. Ways to recognize a faulty toilet float is when water continues to float after the tank is full, toilet continuously running, or tank not filling completely.

6. Toilet Tank

The tank is the upper part of the toilet located at the top, back of the toilet bowl. The tank contains stored water that gets released into the toilet bowl when it is flushed. The handle is attached to the tank which causes water to rush into the toilet when turned.

Toilet tanks are made of porcelain, thus solid. On their own, they rarely get faulty. They may sometimes break or crack. Tiny cracks in toilet tanks can be fixed by drying its inner part and adding silicone plumbing epoxy to the faulty portion.

7. Wax Seal

Flush toilet wax seals are round, cone-shaped seal that fits between the top of the floor flange and the bottom of the toilet bowl. It prevents water from leaking from the toilet. They can be used only once.

If a toilet is leaking at the base, the wax seal may be insufficiently sized for the space or cracked. To fix this fault, you want to remove the toilet. Scrape off the previous wax ring and discard it; afterward, replace it with a new silicone ring or a wax ring.

8. Floor Flange

A toilet floor flange is also called a closet flange. It is a round plastic or metal bracket situated above the sewer pipe extending from below the toilet bowl and the floor. This part is solidly attached to the floor by bolts or screws. The toilet attaches to the flange with the T-bolts.

Floor flanges can get rusty and break when subjected to leaking water. When floor flanges break, it makes the toilet prone to leaks. If your toilet leaks at the bottom, the cause is usually a poor wax seal, a broken floor flange, or both.

The solution is to remove the toilet and the flange and replace it. Afterward, set the toilet back in place.

9. Toilet Bowl

The toilet bowl is the base on which you sit when you go to the loo. It has a large round or oblong hole into which liquid and solid wastes enter. Toilet bowls are usually made of a waterproof material that is resistant to stains – vitreous china.

Inside the toilet bowl is a c-shaped internal trap that functions as a waste carrier – it carries waste away. It also functions as a small reservoir of clean water that acts as a cover against sewer gases.

10. Tank O-Ring Seal

This is also called a tank-to-bowl gasket or mack washer. It is an O-shaped wax washer or rubber gasket that fits between the top of the toilet bowl and the bottom of the toilet tank. Its function is to stop water from leaking out of the toilet tank. 

When an O-ring seal is cracked or poorly installed, the toilet will leak below the tank yet above the bowl. To fix this, you want to empty the tank of water, detach the tank, and replace the tank-to-bowl with a new one.

11. Water Supply Shut-Off Valve

This is an oblong-shaped handhold found on the flexible braided water supply line of water supply. The line for water supply comes from the house’s water supply attaches below the toilet tank. The function of water supply shut-off valve is turn off the water supply to the tank in case of repairs or emergency.

This part of your toilet probably have a plastic handle, meaning that it is prone to breakage if you turn it too tightly. The same water supply line can be recycled if it is still in good condition.

Flush Mechanism of Flush Toilets

The flush mechanism of your toilet is inside of it. Before a flush occurs, you must first turn the handle or push the button on the lid of your toilet tank. This handle or button is attached to a chain inside the tank. When you push the button or turn the handle, you are actually pulling the chain. And doing this lifts the flapper or flush valve it is connected to. This in turn opens the drain hole found in the bottom of your tank, which allows the tank water to rush into the toilet bowl.

The quick introduction of water into the bowl via jets in the rims of the bowl creates suction in the bowl as flush. This suction pulls out anything present in the bowl into your pipes, thus flushing them away.

Types of Flush Mechanisms

Your choice of flush mechanism is essential as it can impact your water bills. There are a few different types of toilet flush in the market today, flushometer valve, touchless flushing, single flush toilets, and dual flush units. Be sure to learn about these types of flush mechanisms below to understand how each of them work.

1. Single Flush

This type of flush mechanism has only one flushing mechanism for both solid and liquid waste. The single flush mechanism is the commonest type of toilet flush you can see in most houses. A common disadvantage of the single flush system is that they consume plenty of water, making them environmentally unfriendly.

Secondly, your flush is likely to break easily, which is a daunty task to deal with.

2. Dual Flush Units

Dual flush mechanism has two flushing option – full flush for solid waste and half flush for liquid waste. This type of flush mechanism is becoming increasingly trendy because they save water which make them budget and environmentally-friendly.

While they might be a little pricier than the single flush unit, they make up for it in the long run.

3. Flushometer Valve

The flushometer use the flushometer valve mechanism, suitable for toilets without tanks. This type of flush unit have a great flushing mechanism and two major components – the flushometer valve and the toilet bowl.

Although the flushometer valve is not very common in residential houses, they are mostly used in industrial, commercial, institutional restrooms.

4. Touchless Flushing

The touchless flush mechanism is motion-sensor activated, making it convenient, hygienic, and modern. With this type of flush unit, you can forget about toilet chains, levers, and flush buttons. This flush mechanism is commonly used in office buildings or public restrooms.

Refill Mechanism

A flush occurs when sufficient water fills the toilet to trigger the siphon. The function of the toilet tank is to send about two gallons of water via the toilet bowl within thirty seconds to cause the flush to occur with a push of the button or pull of the hand. 

Once the tank has emptied its content into the toilet bowl, the flush valve gets shut to enable fresh water to be collected for the next flush session. At this time, the refill mechanism takes effect and carries out its role.

The refill mechanism is equipped with a valve that activates the water supply. The process is signified by the float ball, which drops to half-mast when the tank empties, then rises to the filler valve once the tank is completely refilled. While this is happening, water is also going down the overflow tube to refill the bowl.

The float ball — also known as the filler valve — and the overflow tube work together to keep the water level even during this process. When a flush never seems to end, it’s often due to an issue along these lines.

How Does a Toilet Work?

While discussing the parts of a flush toilet, we highlighted the major idea of how it carries out its role. In this section, we shall bring it all together in a step-by-step form of what happens when you turn your toilet handle or push down the flush button.

a. You visit your bathroom and do your thing. Afterward, you push down the flush button or turn the handle. Doing this pulls the chain.

b. After the chain pulls, it causes the flush valve to be released. It releases roughly one and a half to three gallons of water from the tank into your toilet bowl.

c. The motion and speed of the water rushing into your bowl cause a sucking effect (siphoning) that sucks the waste and everything else in the bowl down into the drain.

d. While the water rushes out of the tank, the water level reduces, thus causing the float to sink.

e. The flush valve reseals. This happens to prevent fresh incoming water from remaining in the tank and not leaving.

f. As the float sinks, it prompts the refill valve to open, thus causing fresh water to fill the tank again.

g. As water continues to flow into the tank, the float rises. It rises until it gets to a level that prompts the refill valve to reclose.

Will a Toilet Flush Without the Presence of a Tank?

Yes, a toilet will flush in the absence of a tank. All that is required to get rid of liquid or solid waste is to make water go up the siphon. And if this is to take place in the absence of a tank, more water is required. For example, if your toilet bowl were to be removed, your toilet bowl would still do the job of taking your bodily waste to the sewer. But then, you will need to make an effort by using water to push down the waste to the sewer.

The curved siphon is even more indispensable than the toilet tank because it is basically what makes the toilet flush in the first place. What the tank and handle do is ease the entire process for you.

Perhaps you cannot imagine how you could flush away waste without a toilet tank; there is a quick experiment that can help you understand the wonders of your flush toilet’s exceptional design:

Notice the water level in your toilet bowl. Afterward, pour a big cup of water and watch to see if the water level changes. You will discover that the water level did not change. But why is this so? It is because the water you added sent some of the previous water over the siphon. Even if you decide to try it again and again, you will notice the same thing. This is so because the siphon limits the amount of water the toilet bowl stores at a given time.  

You might want to try something a little different. Pour a larger quantity of water – say a bucket of water – into your toilet bowl and see what happens. This time, your toilet will flush fully, even though you did not pull your toilet handle.

When this occurs, it is because your siphon tube has become full. And this causes the siphon to suck all the water from the toilet bowl. While this is taking place, the siphon tube is filled with air, and then you hear the loud flushing sound.

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