A toilet flapper is a device, typically rubber, located inside the tank of a standard toilet and designed to allow water to flow into the bowl of the toilet. The flapper can be damaged or deteriorate due to usage and toilet cleaning chemicals, so it should be checked fairly frequently to ensure proper sealing and prevent potentially costly water leaks. A faulty toilet flapper can also be the cause of many simple toilet problems and replacement of the flapper or connector can sometimes repair a seemingly larger issue.
Most standard toilets are designed to have a bowl that contains water into which waste is deposited, with a large tank usually behind the bowl. This tank contains most of the mechanisms that operate the toilet when it is flushed and filled, including the toilet flapper. In general, the design is fairly simple and utilizes gravity to do most of the work in properly flushing and filling the toilet bowl. A standard toilet will typically have water in the tank that is relatively clean, since it comes from municipal sources, and water in the bowl of the toilet.
When a toilet is flushed, the water in the bowl drains away into a sewage system, typically city sewage or a septic system. The flushing usually involves a handle being pulled or pressed, and a chain or rod connected to the toilet flapper lifts the flapper up when this occurs. A toilet flapper is basically a rubber valve that covers the pipe running between the toilet tank and the bowl of the toilet. When the toilet is flushed, the handle pulls the chain or rod up and lifts the toilet flapper out of the pipe, at which point the water in the tank drains down the pipe into the bowl of the toilet.
This action refills the toilet; as the water drains, the toilet flapper floats down with the water until it reaches the pipe and seals it once more. As water comes into the tank through another pipe, the flapper seals off the pipe to the bowl. This allows the tank to fill up with water in preparation for the next flush. If the flapper does not seal the pipe properly, then water can potentially drain from the tank into the toilet bowl, and this leak can amount to a surprising amount of water over the course of a year.
Such a leak can actually result in a substantial increase on water bills, so the toilet flapper should be checked and replaced regularly to ensure a proper seal. When a toilet keeps running after flushing or will not flush when the handle is pulled up, this can often indicate a problem with the flapper, such as the flapper not sealing the pipe or the handle no longer being connected to the flapper. Fixing this type of problem can be fairly simple and quite inexpensive.