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7 Reasons Your Toilet Keeps Running & How to fix it

How to fix a running toilet

A toilet running continuously can be both annoying and worrisome. It’s also a sure sign that you need to fix your toilet! Fortunately, there are many reasons why a toilet may run and most of them are easy to fix. In this post, we will discuss 7 different causes for toilet running, so you can stop worrying about it. Here’s how to fix a toilet that keeps running.


Is it bad if my toilet keeps running?

It may not seem like a big deal, but constantly running toilets are costing homeowners money in higher water bills.

The excess water is constantly flowing out of the tank and down the drain. If your toilet is running, it’s best to stop it as soon as possible. 


What does it mean when the toilet keeps running?

When your toilet is running, it means that the water from the tank is flowing into the bowl one way or another through the drain valve (see the causes above). This means that there is something in the toilet tank that needs to be fixed. 


Reasons your toilet keeps running.

Your toilet will be running for one of several reasons. The best way to approach it is to inspect each of these items below to make sure that it’s one of them and fix where it is needed. Ultimately, there is water leaking from the tank into the toilet bowl due to a faulty part or a water level being too high. Here is what you need to inspect. 


The toilet flapper isn’t closing.

toilet not running flapper broken

A loose or broken flapper can cause your toilet to keep running.

The main source for a toilet to keep running is that the flapper isn’t properly closing. This could be because the flapper is worn out, and it’s not for me to properly seal on the drain. 

A good way to check is to push down slightly in the middle of the flapper while it’s in the tank and see if the running water stops. If everything else seems in place, you will need to replace the toilet flapper.

They come in different sizes, so make sure to turn off the water shutoff valve at the main water line and take the piece into your local hardware store to get the right fitting replacement. It’s also a good idea to know what type of toilet you have.

The flapper should be free of any residue or build-up. Inspect the flapper and make sure it is free of any build-up; removing the build-up could solve your problem. 

Next, check the flush valve (what the flapper sits on) for any cracks or damage. If you see any damage to the flush valve, it will need to be replaced. If there looks like there is build-up, give the flush valve a wipe to see if the build-up can be easily removed. 


The refill tube is too long.

This is the tube that runs from the toilet fill valve into the overflow tube. If the refill tube is too long, the water will go from the toilet tank to the overflow valve, causing your tank to run continuously. Another thing that could result in is ghost flushing. Ghost flushing is where it sounds like your toilet is flushing on its own every so often.

This is because the refill tube is too long and is creating a siphoning effect from the tank into the overflow tube. The tube should be sitting just above the overflow tube. You can get clips (or if you purchased a toilet fill valve, you might have one already), and you want the tube to be sitting just above the tube. Otherwise, it will pull water from the tank into the tube. 

running toilet refill tube

Your refill tube should sit on top of the overflow pipe, or else it could cause your toilet .to run constantly.


The float is set too high.

Another reason that your toilet keeps running is that the float is too high. This can happen if the toilet float arm is bent or the float ball is stuck above the water level. This can happen on older-model toilets that have a ball float rather than a float valve. 

To fix this, adjust the float arm in the float ball to the right level so that it shuts off after the water it’s the soul level on the tank. There will be a screw on the top of the fill valve that can adjust the float ball’s height. 

If you have a newer model, the float cup on the float valve may be set too high, and you will need to adjust it to a lower water level. If the float cup is set, too high water will keep running into the overflow pipe, causing water to run continuously. This can also happen if your toilet was previously filling up slowly and you replaced the fill valve. By replacing the fill valve, you may have set the float cup too high, and that is why it’s now running constantly. 

toilet running because float too high

Use a screwdriver to adjust the height of your float cup so the toilet stops running.



The chain is too short.

Another reason for the flapper not closing is that the chain going from the lift arm to the flapper is too short. If there is not enough slack in the chain, the flapper will not fully close, and the seal won’t properly form, causing water to go down the drain valve and into the toilet bowl.


fixing a running toilet

Make sure your toilet chain is not too long or too short when fixing your running toilet.

The chain is too long.

The opposite can also happen if the flapper chain is too long. The slack in the chain could get caught in between the flapper and the drain valve, causing the flapper not to seal properly, and the water will continue to run. 

This is often the case when you have a toilet that keeps running intermittently. If you find that your toilet runs sometimes and doesn’t at other times. It could be that the chain is sometimes getting stuck in between the flapper in the drain valve, and other times it’s not. To fix this, shorten the chain. 

Toilet Handle Chain Stainless Steel Toilet Flapper Lift Chain Replacement Fits Most Toilet Flappers (3)

Broken Float Valve

When you inspect the fill valve and fill tube, the casing could be cracked, causing water to leak out of it continuously. If this is the case, you will need to replace the fill valve with a newer model. It’s a fairly cheap repair and easy to do.

Fluidmaster 400AKRP10 Universal All in One Toilet Repair Kit for 2-Inch Flush Valves, Easy Install, 2 inches, Assorted Colors

The overflow pipe is cracked.

Another thing that is less common is that the overflow pipe is cracked. This will cause the water to leak through the overflow tube and down into the bowl, causing your toilet to run or cycle running on and off over time continuously.


How do you fix a toilet that keeps running?

If your toilet won’t stop running, here’s how to fix a running toilet.

  1. Turn off the water supply at the shutoff valve below the toilet.
  2. Remove the tank lid of the tank and put it somewhere out of the way where it won’t get damaged.
  3. Check the items mentioned to see where the water leak is coming from. 
  4. Repair the leak once you have identified where the water is leaking using the methods above.
  5. Turn the water supply back on.
  6. Replace the tank lid back on the toilet.

Related: How to fix a toilet tank that isn’t filling up

Final thoughts on how to fix a running toilet

A running toilet shouldn’t be ignored for too long. It is usually an easy fix that you can do on your own with minimal tools and a few step-by-step instructions. If none of these is your issue, you may need to bring in a professional plumber to help you with further identifying the issue.


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