What Causes The Toilet Water To Run Continuously?

If your toilet is constantly running, it can be quite a nuisance. Toilets are expensive, so the thought that you may need to replace it can be overwhelming. Thankfully, there are quite a few ways to diagnose this problem independently.

If your toilet water runs constantly, you have a worn-out flapper, misaligned fill tube, or faulty float. It could also be a water level that’s too high. You can fix most of these issues yourself quickly to get your toilet working properly again.

What Causes The Toilet Water To Run Continuously?

Let’s talk about each of these reasons in more detail and see what you can do to fix them.

5 Reasons Why Your Toilet Water Won’t Stop Running

1. Water Level Set Too High

The water level setting is one reason your toilet may continue to run even when you aren’t using it.

Toilets use water for flushing but if the level is too high, it can result in the toilet running more that it typically should.

The first step in checking if your water level is too high is to find the fill tube.

This component is responsible for pumping water into the toilet’s tank, and this allows it to fill up.

The level is appropriate if the water is about one to two inches (5 cm) below that tube.

If you notice that the water is very close to the fill tube or has submerged it, then you need to lower the water level in the tank.

If you are still unsure whether or not the tank is too full, there should be a fill line located inside the tank.

Most likely, you will find this line etched into the porcelain.

So, take the time to find the line and see if the water is above it.

You can resolve this issue by shutting off the water supply to your toilet.

Once it is off, locate the screw on top of the fill valve.

If the water level is too high, tighten this screw to lower the anticipated water level.

Ensure you do not overtighten it, or the tank will not hold enough water to flush strongly.

Once you allow water to run into the toilet again and flush it, the toilet tank should now fill to a new level.

Ensure you get it as close to the expected fill line as possible.

Tighten the screw to lower the level and loosen it to allow more water in.

This may take a few tries to get right, but it should prevent the toilet from running constantly.

2. The Chain on the Flapper Is Loose or Broken

Looking at the inside of the toilet, there is a chain connecting the flapper to the toilet lever.

The chain connects these two components, which are essential for toilet flushing.

If the chain is loose or broken, it may not lift the flapper properly, which can result in your toilet not filling up correctly. It can also cause your toilet to run for longer than it should.

First, we recommend you check the chain for any breakage or damage.

This is the easiest problem to spot.

If the chain you have a broken chain, you will need to replace it with a new chain for the toilet to work properly again.

If the chain is still intact, it may be loose.

To test this, feel how loose the chain is when you close the flapper. If the chain still has a lot of give, then it is too loose.

You can tighten it easily by switching to a different link in the chain. Allow it a small amount of give, about an inch, when you close the flapper. It doesn’t need more than that.

If you close the flapper and the chain rests on the button of the tank, then you have way too much give in the chain.

So, make sure you tighten it enough that it no longer touches the bottom yet still allows the flapper to close.

3. Worn Out Flapper

What Causes The Toilet Water To Run Continuously?

Flappers can harden or warp over time as they remain consistently submerged in water.

So, it is common for them to wear out long before the toilet does.

A worn-out flapper can allow the tank to leak consistently into the bowl even when it should stop.

This happens because the flapper is not able to block the flow of water completely like normal.

However small, this constant stream of water can cause your toilet to run all the time as it struggles to remain full when it should be stagnant.

The best thing you can do is shut off the water to the toilet so it stops constantly trying to stay full and replace the flapper.

Remove the flapper from the chain and purchase a new one.

Flappers are small, rubbery, and pretty cheap. So, you can find a decent replacement for around $10 to $20.

The flappers come in two-inch, and three-inch options, so make sure you choose the one that fits your toilet.

Once you have your new one, reattach the chain to the new flapper, turn the toilet water back on and test it out.

4. Misaligned Fill Tube

The fill tube, sometimes referred to as the refill tube, is the means by which water gets into the toilet tank.

The tube pulls water into the tank until it reaches the designated fill line, at which point the water stops coming in.

The fill tube may become misaligned over time as the toilet gets older and used more often.

The fill tube is made or rubber and is flexible, and this makes it vulnerable to getting forced into the toilet’s overflow tube.

This can cause it to not fill up as much as it should and consistently run.

Check how far submerged the fill tube is inside of the overflow tube.

It should only go about an inch inside of the overflow tube to remain working properly.

If the fill tube is further down into the overflow tube than about an inch, adjust the tube to allow the proper distance.

This will help the toilet tank fill better and allow the toilet to run less.

Also, check the fill tube for any damage or possible disconnection.

Even if the fill tube is exactly where it needs to be, any damage can cause it to not fill the tank properly.

You can replace the fill tube if there is any damage, but most of the time, you can resolve this by checking to ensure it is tight.

5. The Float Is Not Working Properly

If the float in your toilet is not working as it should, then your toilet may run constantly.

The float is at the top of the toilet tank, and it is responsible for determining the proper fill amount of the tank.

If it stops working, the tank may continue to fill up even though it is already full since the float did not indicate the water is high enough yet.

If this happens, the water may leak out of the tank and onto the floor.

However, before this occurs, the additional water coming from the tank will come into the overflow tube.

The tube will then cause the water to go into the bowl, resulting in a higher water level.

Because of this, the tank will continue to run because it is unaware that it is already too full.

There are two different types of floats in toilets, a ball float, and a column float.

For both varieties, it’s advisable to have a float set that is roughly one to two inches (2.5 to 5 cm) under the overflow tube.

This will allow the tank to fill without risking overflow and constant running.

If you see that it has been set too high, turn off the toilet’s water supply, and change the float’s position accordingly.

Adjusting a Ball Float

Use a screwdriver to loosen the float to adjust a ball float and prevent the tank from overflowing.

You can find these screws at the base of the float.

You don’t need to completely remove these screws.

Just loosen them enough that the ball float begins to move downward.

Adjust it until it is about an inch or two from the overflow tank.

Doing this can cause you to make the float too low, not allowing the tank to fill up enough.

That’s fixable as well. Just tighten the screws a little until the ball float is at the right level.

After turning the water back on, flush your toilet to check if the level is normal.

You might need to do this several times until you achieve a suitable water level.

Adjusting a Column Float

What Causes The Toilet Water To Run Continuously?

Column floats are a little bit different.

Rather than unscrewing anything, you will instead need to locate a clip on the tube that connects the float to the valve.

When you find this clip, you need to tighten it to be able to adjust the float.

If done correctly, you will feel the float give.

Keep applying pressure to the clip and move the float to the desired height.

You may have to do this a few times to get it right.

Once you have adjusted the float, release the clip, refill the tank, and see how much it fills up.

Getting it right may take a few tries, but it will stop the tank from overfilling.

Final Thoughts

A constantly running toilet can be a major concern and also a nuisance.

Thankfully there are plenty of reasons this can happen that you can fix.

Of course, make sure you turn the toilet water off before performing any maintenance to avoid flooding.

If the problem persists, we recommend contacting a plumber for further help.

Cheers, tools owners!

Hi there! My name is Jack and I write for ToolsOwner. I have a passion for everything related to tools and DIY projects around the house. You often find me in my workshop working on new projects.