How Do Toilets Work?


Toilet Basics: Understand How They Work

I had a situation today that made me realize that common toilet knowledge is probably not so common!  The basic functioning of a toilet as well as the non functioning aspect of a problem toilet, might not be understood by the majority of homeowners.  

Basically this is how a normal gravity toilet works.

  1. The toilet consists of a water tank, that normally sits on the rear of the toilet assembly, a toilet bowl, which is the container that holds water and eventually whatever is deposited in the bowl, and the toilet seat, which sits on top of the toilet bowl to make the use of the toilet a little more comfortable.  
  2. There are only two plumbing connections required for a toilet to function.  A waterline must be connected to the water tank to allow the tank to fill after the toilet has been flushed and the sanitary connection, which is the piping system that accepts the waste that is deposited in the toilet and directs this waste to a sewer line or a septic system.
  3. The interior of the water tank has mechanical mechanisms that allow the user of the toilet to flush water from the water tank into the toilet bowl, which causes the waste deposited in the toilet bowl to be flushed down the sanitary line, which is located below the toilet bowl. 

That is basically the total function of a common toilet.   There are no special mechanical or electrical pumps or devices that cause the toilet to flush and function.  Fluid mechanics takes care of all of the actual action of a toilet. The position of the water tank, the fluid dynamics of the bowl with water either entering or exiting, all works to allow the normal gravity toilet to flush.  

Yes, there are various special toilets that are “ super charged “ to promote a special power flush that adds pressure and additional performance to the normal gravity flushing occurence of standard toilets.  However, this “ power assist flushing “ is not necessary for the functioning of a normal, everyday toilet.

What can go wrong?

There is not much that can go wrong with a standard toilet aside from the most obvious.

  1. The toilet is clogged.  What his means is that there is an obstruction in the sewer line or in the toilet itself that is preventing the water and whatever was deposited in the toilet bowl from being flushed down the sanitary line. Clogging can occur from various different scenarios.  If someone has deposited a large amount of material and then decided to use substantial toilet paper to clean up, this simple use of the toilet, can clog up the flush of the toilet. Someone dropped a comb, a toothbrush, a pen down the toilet and flushed this down.  Whatever was dropped into the bowl can clog up the clean and efficient flow of the water down the sewer line. Clogging can occur from anything that cannot be flushed down the toilet without clogging.
  2. The toilet is always running.  What causes this is a water leak of seepage.  A leak that causes a toilet to “ run “ continuously is not normally the type of leak that will cause damage or mold.  A running toilet is normally construed as a constantly or intermittently running toilet that has water flowing within it’s system of toilet bowl, tank, sanitary line, etc.  A toilet that is running all the time or intermittently without anyone flushing the toilet simply means that there is a leak or an issue with the water tightness of the entire system.  In most situations, this is an issue with the mechanism within the water tank that holds the water that is used to flush the toilet. A simple replacement of the interior mechanical system within the water tank itself, will normally solve the “ running “ problem.
  3. There is water around the base of the toilet.  In almost all cases, this will mean that the connection between the toilet bowl and the sanitary line which exits below the toilet bowl has been compromised.  This connection is watertight with the use of a what is called a wax ring. This wax ring is located between the bottom of the toilet and the start of the sanitary line that directs the waste down to the sewer line. This situation can be caused by someone rocking the toilet when they are on it, or someone that is very heavy and compressed the entire connection to such an extent that leaking occurred.  
  4. In very rare occurrences, the vent could be clogged or compromised for some reason.  Each sanitary line that exits the home is connected to a vent pipe that goes through the roof.  This vent pipe supplies the air to balance the piping system when something goes down the sanitary line.  If there is no vent, the sanitary line will not function due to the vacuum that is created within a closed piping system.  This could occur if for some reason the vent was clogged and stop the proper flushing of the toilet, however, this is rarely the issue.

The correction to all the normal toilet issues, is in most cases, extremely simple.  The toilet function as well as the repair should not be a major issue, and any professional will be capable of correcting any toilet problem without an issue.  

The most serious problem that can occur with a toilet that is not functioning, is the limitation of the sewage disposal area, such as a septic system of the actual sewer discharge line exiting out into the primary sewer line in the street.

Toilets are extremely simple mechanisms and their repair and or replacement is normally not a big deal.