A toilet is leaking on the floor

Why is my toilet running?

Your toilet is making that sound again. You know the one—that annoying noise where the toilet constantly runs. What causes this to happen?

A running toilet is basically an internal water leak, so we need to examine the internal parts in the tank that are allowing this to happen.  Don’t ignore this problem, because a running toilet could be wasting hundreds of litres of water a day, running up your water bill.

We’ll explain some basic ways to troubleshoot your toilet to get it to stop running.

TIP: There’s a variety of parts in a toilet that you may be unfamiliar with. Use this anatomy of a toilet from toiletology.com to understand what parts we’re referencing.

Check the toilet flapper for decay or cracks

Here’s the most common cause of a running toilet. Your typical toilet tank has a flapper that seals the water in the tank.

You see, when you flush the toilet, this raises the lift arm in the tank, pulling on a chain (or lift wire) that’s attached to the toilet flapper, raising it up and allowing water to go into the toilet bowl.

Once enough water exits the tank, the flapper drops back down, re-sealing the tank.

However, if the flapper (or the valve seal) is cracked, water will keep seeping into your toilet bowl, causing it to run constantly. If this is the problem, turn the toilet’s water supply off by turning the cutoff valve clockwise. Flush the toilet. Use a sponge to get rid of any leftover water.

Now you can unhook the flapper and replace it. Your local hardware store should carry them.

Check the chain

While we’re on the subject of toilet flappers, check to see if the chain’s length is causing the flapper to not seal properly. If the chain is too long, it can get caught under the flapper. You can easily unhook the chain and hook it to another level of the chain to shorten it. Just don’t make it too short of the flapper won’t seal at all.

Examine the toilet tank float ball and float arm

Take the top off your toilet tank and you might see a big plastic balloon. That’s the float ball which is connected to a float arm. When you toilet’s tank is filling back up with water after you flush it. It knows when to stop when the float ball rises to a certain point.

Lift the float arm. If the running stops, then you’ve gotten close to finding the problem. The float ball isn’t high enough to stop the water from running. One reason could be that the ball is rubbing against the side of the tank. Bend the float arm slightly to move the ball away from the tank wall.

If the ball isn’t touching the side, then the ball may have a crack. If there’s a crack, the ball will fill up with water and sink down like a canoe taking on water. This causes your toilet to keep bring in more water. The excess water goes down an overflow tube which feeds into your toilet’s bowl, causing the constant running noise.

If this is the case, you’ll need to replace the float ball.

Did none of these suggestions help?

If the toilet flapper and the float ball aren’t the problem, it’s possible the entire ballcock assembly needs to be replaced. Your local hardware store carries ballcock assembly kits. These come with instructions for how to install them.

If you’re still having trouble or would like a professional to ensure your toilet is repaired with a guarantee, contact Son Plumbing and we’ll be happy to help.