Welcome to Toilet School

As simple as toilets may seem, they can be quite complicated!

Most people are familiar with the basic components that make up the outside of a toilet – the tank, bowl, flush handle, etc. – but what are the parts inside of the tank? What do they mean? What do they do?

If you want to learn more about the ins and outs of your toilet, then you’ve come to the right place!

The Different Parts of a Toilet

Inside your tank, there are six main components that allow your toilet to function properly:

Diagrams of Different Toilet Tanks

1. Handle: Located on the outside of the tank. Pushing it down will start the flush cycle. Newer toilets may have a button or touchless sensor.

2. Lift Chain: Connects the handle to the flapper. Pushing down on the handle raises the flapper off the flush valve.

3. Flapper/Flush Valve: The flapper is the round, rubber device positioned on the bottom of the toilet tank covering the flush valve. When the handle is pushed down, the flapper opens, allowing water from the tank to rush into the bowl (through the flush valve). After the flapper closes onto the flush valve, the tank and bowl refill with water.

4. Float (ball or cup type): Controls the opening and closing of the fill valve. As the water height drops in the tank, the float opens the fill valve. As the water rises, the float closes the fill valve.

5. Fill Valve: Controls water flow into both the toilet tank and bowl. The fill valve has upper and lower ports which open and close simultaneously. The lower port refills the tank, while the upper port refills the bowl through the overflow tube by way of the refill tube.

6. Overflow Tube: During normal function, water from the fill valve flows through the overflow tube in order to refill the toilet bowl. However, if the fill valve does not shut off properly and contines to fill the tank, excess water will drain through the overflow tube into the bowl.

What is a Flush Cycle?

The flush cycle is the time it takes for the toilet to clear waste from the toilet bowl and refill with water.  The flush cycle can be broken into two phases – evacuation and refilling – with a brief (1-3 second) pause between each phase.  Depending on the model of toilet, water pressure, and how well your toilet is working, the flush cycle can be as short as 15 seconds to as long as two minutes.

The evacuation phase begins when you push the flush handle (or button).  This lifts the flapper and opens the flush valve, allowing water to rapidly evacuate from the tank and into the bowl.  The force of the evacuating water creates a siphon effect, pulling the waste from the bowl and into the drain.  The float, which rises and falls with the water height in the tank, drops to the lowest point in its cycle.  When this occurs, the fill valve turns on, beginning the refill phase.

The refill phase begins when the flapper drops, closing the flush valve.  The lower port of the fill valve begins to fill the tank with water, causing the float to rise.  At the same time, the upper port of the fill valve refills the bowl through the overflow tube.  Once the water height raises the float to the top of its cycle, the float closes the fill valve with a “snap action”.  The tank and bowl are refilled with water, and the toilet is ready for another use.

What is a “Phantom Flush”?

Have you ever heard your toilet periodically make a noise that sounds like the water is running, but it hasn’t been flushed recently? What you’re hearing is called a phantom flush, the unintended and unseen escape of water from a toilet that is not operating correctly.

A phantom flush occurs when water leaks from the tank into the bowl due to a faulty flapper (or another similar failure). As the water level inside the tank goes down, the float drops. This opens the fill valve briefly, allowing it to refill the partially empty tank.

If the failure causing the phantom flush is not corrected, a repetitive cycle of leak…fill…leak…fill is created. This cycle can waste 50 – 200 gallons of water every day, making leaking toilets the #1 cause of unintended water use in the home.

Diagram of a toilet with phantom flush

What causes a “Phantom Flush”?

Below is a list of reasons why the repetitive “Phantom Flush” cycle can occur.

  • Flapper is not sealing properly because:
    • It’s the wrong size or model for your toilet.
    • Something is stuck under the flapper lip.
    • It has deteriorated or warped from hard water and/or cleaning solvents.
    • It is physically defective.
    • It has a pinhole in it.
  • The chain is not working properly because:
    • It’s too short and holds the flapper open slightly
    • It’s too long and gets stuck under the flapper
    • It gets kinked and holds the flapper open
  • The fill valve stops working correctly (leaks or doesn’t fully close)
  • The float height is set improperly
  • Fluctuations in water pressure throughout the day
Dye Tablets

5 Reasons why dye tablets are not accurate:

The LeakAlertor takes away the frustration of high water bills, and saves you money! Unlike dye tablets, the LeakAlertor is constantly at work checking for silent leaks, wide-open flappers, and faulty fill valves. It alerts you before you leave the bathroom with a “beep” and blinking LED during the flush cycle.

1) Errors are made in using dye tablets.
Often times, dye tablets are used incorrectly. Some people have mistakenly put the tablet in the toilet bowl rather than the toilet tank…test ruined! Some have put the tablet in the tank, and flushed the toilet immediately…test ruined! Some people drop the tablet in the tank, but then walk away and forget…again, test ruined!

2) Not all toilet leaks are caught by dye tablets.
Dye tablets can only detect one type of leak – a leaking flapper – and only if it’s leaking at the time of the test. However, stuck flush valves, wide-open flappers, phantom flushes, and running toilets are all common leaks not detected by dye tablets.

3) By the time you use a dye tablet your toilet may have already been leaking for weeks, or even months.
Often times, homeowners don’t realize a toilet is leaking because they think a leak should mean there is water on the floor. However, the most common leaks occur either at the flapper, or where the tank and bowl connect. These leaks occur inside the toilet, and are almost always invisible.

4) Intermittent leaks are often missed by dye tablets.
Just because your toilet isn’t leaking at the moment of testing doesn’t mean it wasn’t leaking an hour ago, or won’t be leaking an hour from now. Also, when a flapper first begins to leak, the amount may be too small for dye tablets to detect.

5) It’s not easy to get dye tablets.
Few hardware stores actually sell them, and it’s a hassle to contact your water utility for free tablets. You can buy them on-line, but you have to pay for shipping and wait for them to arrive. Meanwhile, your toilet continues to leak, and your water bill gets even higher!

7 Reasons why the flapper/flush-valve won't close:

1)  The flapper is “stuck” to the overflow pipe.
One observable symptom: it is not bobbing or floating in the water, regardless of the water height, and appears to be partially or fully upright.

2)  The chain is tangled.
A chain link can get stuck on the metal clip or loop over the top of the lever arm. Although an improper chain length causes many of these problems, “slapping” the flush handle can also cause the chain to hang up.

3)  A clogged drain/obstructed pipe produces back pressure through the flush valve seat.
The obstruction doesn’t allow the water level inside the tank to drop low enough for the flapper to seat properly. In this instance, the flapper appears to “hover” in the water above the flush valve seat. A clogged or obstructed drain pipe is the most common reason for toilets to overflow the bowl.

4)  A “universal” replacement flapper is purchased.
When a “universal” replacement flapper is purchased, it does not seat properly on the flush valve. Flappers should be purchased according to the type of flush valve used because universal flappers can leak and/or fail to seat up to 50% of the time.

5)  The flush handle/lever is old, defective, or “sticking” to the inside of the toilet tank.
Old or defective equipment can result in the flapper being held open.

6)  The flapper hinges are weakened and/or degraded.
This allows the flapper to slide to the side and not seat properly on the flush valve. (Note: the water flow from the fill valve can also push the flapper to one side if it is above 60 PSI.)

7)  A flapper’s buoyancy doesn’t become “negative” until the tank completely evacuates.
This does not allow the flapper to seat properly. Although there are several known causes (including toilet design), the most common is a clogged or obstructed drain pipe, which creates back pressure into the tank through the flush valve.

5 Common reasons why wide-open flappers often go undetected:

1)  No one is home to hear it running.
Often times, a person will use the bathroom before they leave their home (or business). In this case, a wide-open flapper would not be detected until the person returned home and realized the problem. This could be hours, or even the following day.

2)  The bathroom is not used frequently.
A wide-open flapper in secondary bathrooms (a finished basement or guest bathroom) can go undetected for days or weeks, wasting a tremendous amount of water and resulting in a high water bill.

3)  Hearing impaired/challenged people may fail to recognize a problem exists.
People with moderate to severe hearing loss may be unable to hear the running water. People afflicted with tinnitus may be unable to distinguish the sound of the running water from their tinnitus.

4)  The sound of the toilet tank refilling is a muted hum.
The initial flush of a toilet is loud, brief, and occurs while the user is still in the bathroom. However, the refilling of the toilet is quieter, prolonged, and typically finishes after the user has left the bathroom. Therefore, the user is unaware when the flapper remains wide-open.

5)  Background noise can easily mask the sound of a wide-open flapper or flush valve.
Examples include central air conditioners and HVAC systems (while the fan is operating); ceiling and window fans; music and/or TV; etc.