A toilet tank empties when the flapper is improperly seated or worn out.
When your toilet is working properly, a rubber stopper called the flapper opens when you flush, allowing water to empty from the tank, and then reseats so the tank can refill. If your tank empties by itself, there may be something wrong with the flapper or your tank may be loose or cracked. The sound of the toilet valve cycling on and off or running nonstop usually alerts you to the problem. Does this Spark an idea?
The Toilet Flapper
When you flush, a chain attached to the handle lifts a rubber stopper called the flapper off of the siphon tube in the bottom of the tank where it is seated. The flapper has a rounded underside so it fits in the tube, and it has two rubber ears that hook onto the fill valve. It stays up as long as water is flowing out of the tank and falls back into place when the tank is empty. As the tank refills, the weight of the water pushes down on the flapper to seal it.
Misadjusted Chain
If the chain connecting the flapper to the toilet handle is too short, it can prevent the flapper from falling all the way down and making a seal. Sometimes the chain hooks around the fill valve or gets hung up on the float. In either case, the tank will keep draining until you fix it. Unhook the chain from obstructions. To lengthen it, simply unhook it from the handle, let the flapper fall, and hook it back so the chain is a few links longer. Don't make it too long, or the flapper won't lift when you push the handle.
Worn out Flapper
Rubber flappers tend to wear out with age, and when one does, it doesn't make a seal and water leaks out of the tank. If you can't tell if the flapper is worn, put dye in the tank and watch for the color in the bowl to change. Replacing a worn-out flapper is a fairly easy job, and flappers are inexpensive, so you don't have to let the leak continue. Turn off the water, flush the toilet, unhook the flapper ears from the fill valve and disconnect the chain. Hook the new one to the fill valve, connect the chain and turn on the water.
Leaking Tank
More serious than a flapper problem is a cracked tank or loose connections between the tank and the bowl that are allowing water to spill onto the floor. You'll usually notice water collecting on the floor behind the toilet but not always. Water can drip along the outside of the toilet, seep under the toilet and soak into the subfloor, creating serious problems if you don't stop the leak. Secure the tank connections by tightening the screws inside the tank with a long slot screwdriver. If the tank is cracked, you'll have to replace it.
Tags: fill valve, allowing water, called flapper, rubber stopper, rubber stopper called