A running toilet is not only annoying; it can also be costly. It's not uncommon for even an intermittently running toilet to waste nearly 30 gallons of water per day. That is why it is important to resolve the issue by getting it repaired as soon as possible. Below are some common reasons why toilets run and what homeowners can do to fix the problem:
Poorly Adjusted Float Valve
Toilet tanks contain two types of valves: a fill valve that controls the intake of fresh water and a flush valve that releases water into the bowl. The fill valve uses a mechanism to regulate the water level inside the tank and automatically turns on whenever the water isn't at its preset resting level. Once the water reaches the predetermined level, the fill valve turns off and prevents additional water from entering the tank.
The most common mechanism used to regulate the water level is a float connected directly to the fill valve. As the water rises inside the tank, the float also rises and closes the valve. When the toilet is flushed and water leaves the bowl, the float drops into the void and opens the fill valve.
This simple mechanism works well in most cases, but a poorly aligned float can cause the valve to never shut off completely. You will be able to make this diagnosis by observing water spilling over the drain tube inside the tank.
If the float valve is the source of the trouble, then the key to correcting the problem is often a matter of simply adjusting the float height. Many toilets use a screw mechanism that pushes the float up or down; this screw can be easily and quickly adjusted by most homeowners with a screwdriver.
Look for the adjustment screw near the connection between the fill valve and the float arm. Turn the screw slowly clockwise or counterclockwise to determine its effect on the water height and fine tune the operation of the fill valve.
If the float valve does not have an adjustment screw, then you can manipulate the brass float arm to control the water height. To do so, grasp the float itself firmly in one hand and also keep a firm grip on the fill valve assembly with the other. Next, push the float downward to bend the float arm so it forms a bow-shape. You may need to bend the float arm a few times to find the right spot, but always be careful not to damage the fill valve while applying pressure.
Worn Flush Valve
The other valve that releases water, the flush valve, consists of a pliable flapper that covers the opening at the bottom of the tank leading to the bowl.
This component, which is often made of rubber, can become brittle over time due to prolonged exposure to hard water, cleaning chemicals inside the tank or other environmental factors. The seal between the flapper and the opening then leaks, which starts a constant trickle of water into the bowl. The fill valve will turn on and off repeatedly in order to keep the water level up.
Fortunately, replacing the flapper is simple in most toilets. To remove the old one, remove the flapper "arms" from both sides of the drain tube and lift the flapper upward. In addition, remove the flush chain that operates the flapper, and the flapper can then be removed from the tank. Installing a new flapper involves performing the opposite procedure, so be sure to pay attention to how everything comes together.
If the flapper seems to be in usable condition, you should also check the area around the opening at the bottom of the tank. The flapper rests tightly against the opening due to water pressure, but any type of residue that settles between the flapper and the area inside the tank can interfere with the watertight fit. Once again, should the seal be compromised, water will leak and cause the toilet to run constantly.
To correct this problem, you can use a cloth or plastic brush to scrub the lip around the opening and remove deposits. If you wish to clean it more thoroughly, you will need to turn off the water supply to the toilet and flush the tank completely. Use a clean cloth and rubbing alcohol to clean the opening thoroughly and remove all debris.
If you don't feel up to the challenge of performing your own repair work, contact a professional plumber as soon as possible. They can fix these problems above or any other toilet troubles you may be experiencing.