How to Fix a Continuously Running Toilet

By: Ezra Plank

A toilet that runs continuously is not only noisy. It wastes LOTS of water! Fortunately, there are some easy "fixes" that you should try first, before calling your plumber.

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First let's take a look at how a flush toilet works. There are many different types of toilet flushing systems, but most of them have essentially the same functional parts.

Components that bring about the flush:

  • A lever connected to the toilet flush handle. This raises:
  • The lift chain, which in turn raises:
  • The flapper, which allows water to run out the bottom of the tank, and flush the bowl.

After a flush, the water level in the tank falls, which initiates a chain of events that fills the tank back up with water.

Components that fill the tank back up with water:

Fixed toilet! by cbb4104, on Flickr
Flushing system using the new plastic float.
  • The fill valve prevents water from entering the tank until it is flushed.
  • As the water level drops, a float connected to the valve sinks, causing the valve to open.
  • Water flows out through the fill tube, into the overflow pipe, and thence into the tank.
  • When the tank is empty, the flapper drops into its valve seat, stopping the flush, and causing the water to rise again.

As the water rises, the float goes up with it, until it reaches its highest position, and shuts the input valve again.

If the water in your toilet is continually running, the problem lies with one of the components above.

How do I fix the running toilet?

I actually managed to fix a running toilet, go bob by etrepum, on Flickr
The old ball float.

Even if you are not experienced in plumbing repairs, there are several things you can do that may take care of the continually running water.

  1. If your float is the old "ball" type, lift it up by hand. If the water stops running, this is your problem. The metal float arm attaching the ball to the input valve needs to be bent downwards. This should shut off the running water.
  2. If that didn't fix the problem, take a wooden stick, and push down on the flapper. If the water stops, this means the flapper is not sealing properly. You should buy a new flapper of the right size. Before installing it, don't forget to first turn off the water and empty the tank.

If the two easy fixes above don't solve your running toilet, and you feel confident about your plumbing skills, by all means try other solutions. You can either use your home repair guide, or search for more advanced techniques on the internet.