A toilet flushes, refills the tank, and then stops automatically. That’s all most people ever notice. When there are issues such as running toilets, leaking tanks, etc., it is important to know what’s actually happening inside the toilet tank.
Toilet tanks are a simple piece of plumbing because only a few parts work together to control the entire process. If one of these parts malfunctions, it will be evident throughout the entire toilet’s operation; therefore, if you know your basic toilet parts, you will be able to predict some problems before they become larger issues.
The Two Main Parts of a Toilet
A toilet consists of two basic parts: the tank and the bowl. Everything else is contained within these two parts.
The tank holds the water at a pre-determined level and determines when it will be released. The bowl is the part of the toilet that creates a flush and directs the waste to the drain. Most problems that you will be working on are with the tank rather than the bowl because the tank has all of the working parts.
Inside the Tank: Where Everything Happens
If something sounds off, runs too long, or doesn’t stop, the issue is almost always in the tank. These are the parts doing the work and moving in unison every time you flush.
Fill Valve
The fill valve is what controls how water enters the toilet tank. When flushed, the fill valve opens and immediately refills the tank with water. Once the proper water level is met in the tank, the fill valve shuts off. If the fill valve does not shut off properly, the toilet will continue to run, and a running toilet can increase your water bill!
The fill valve is one of the most common failure points in the tank.
Toilet Float Ball
The float is the piece inside the toilet tank that tells the fill valve when to stop. As the water level in the tank rises, the float will rise with it. When it reaches an adjustable height, it shuts off the fill valve. If the float is adjusted too high, the tank will overflow, and the water will run into the overflow tube. A float that is off or stuck can cause the toilet to run continuously.
Flapper
The flapper is the closing mechanism located at the bottom of the toilet tank. When the toilet is flushed, the flapper will rise and allow water to flow quickly into the toilet bowl. Once the tank has drained, the flapper falls back into place and seals the opening. If the flapper does not seal properly against the flush valve, the toilet may keep running or refilling. Sometimes the flapper can become worn or out of round.
Flush Valve
The flush valve is located at the bottom of the tank where the flapper sits. It is the opening through which water flows from the toilet tank to the toilet bowl during a flush. Most people do not think about the flush valve, but the seal around it can wear out or become damaged, causing leaks or poor flushing.
Overflow Tube
The overflow tube is located in the toilet tank to prevent overflow of the toilet tank. The overflow tube redirects water into the bowl (not all over the floor) if the water level in the tank rises above the recommended level. If water continues to flow into the overflow tube, your toilet will continue to run. This indicates that the toilet system is not shutting off where it is supposed to.
Handle and Chain
The handle and chain are how you physically operate the inside of the toilet tank. When you press down on the handle, the chain will pull the flapper up, and the flushing cycle will begin. If the chain is too tight, the flapper will not close properly. If the chain is too loose, the flapper may not open all the way. If the chain gets wrapped around itself, the system will not work as it should. Many modern toilets have two interlocking “buttons” instead of a handle. One is for liquid waste, and the other is for solid waste. These act as water-saving devices.
Inside the Bowl: What You Don’t See Working
The bowl doesn’t have moving parts, but it’s designed in a way that makes the flush work.
Rim Jets
Rim jets are located under the rim of a toilet bowl, and water is released through them to direct water around the inside of the toilet bowl when you flush. If the rim jets become blocked, it will not be as powerful and effective when flushing.
Trapway
The trapway inside the toilet is the curved pathway that carries the waste to the waste drain. It also holds water at the bottom of the toilet (a water barrier/trap) to prevent any sewer gas from coming back into the bathroom through the toilet drain. The water that you see sitting in the toilet is meant to be there; it is part of the toilet design.
Wax Ring
The wax ring is the component that is used to seal the toilet to the drain line. It is located between the bottom of the toilet and the floor drain flange. While you cannot see the wax ring, it is an important component of your toilet. If the wax ring fails or has not been properly installed, you will begin to see water leaking around the base of the toilet. That’s not something to ignore.
Why This Actually Matters
Most toilet issues are not random occurrences – they are the result of a part becoming worn out, shifting, or not sealing properly. When you have a toilet that runs continuously, typically it is due to either the flapper valve or the fill valve; if your toilet doesn’t flush very well, it is often due to either the rim jets being plugged up or internal buildup; and if you discover water on the floor, it is often due to the wax ring being allowed to wear out.
Once you can identify each part of the toilet, you begin to recognize patterns of how those parts function together as a system.
Final Thoughts
A toilet is not a complex machine; however, it is not just one piece of equipment either – it is a system made up of many parts. The water enters the tank, the water flows through the tank, then flushes from the tank to the commode, all parts working together until the water stops flowing.
When one part of the system fails, it does not take long for the other components within the system to experience difficulties. If the problem is severe, the malfunction may be extremely noisy, or it may be very visible. If the problem is a minor issue, it may simply cost you more money due to higher utility bills or higher repair bills from damage done to walls/ceilings/etc, each time something goes wrong with the system.
Read more here about What Causes A Toilet To Run
Having knowledge of the components of a toilet does not make someone an expert plumber; however, it does make them harder to surprise when something does fail.
