Having a functional toilet is not only important but mandatory for living. When you are using a toilet normally, you should expect to use 5 to 15 gallons of water per person, per day, depending on how much you use the toilet.

If you start to notice your usage is suddenly a lot higher on your water bill., it may be a sign that your toilet is running. 

How Many Gallons Does a Running Toilet Use Per Day 

If you have a running toilet, it can waste 4.5 gallons of water per minute. If this sounds like a lot, that is because it is! It is almost 300 gallons per hour or 6,480 gallons per day). Not only is this terrible for the environment, but it can increase your water bill by almost $60 per day!

The cause of most leaks is due to a part in your toilet. When toilets get older, the parts do too. In these cases, you will need to replace the parts and your water usage should go back to normal. The only trouble is you will need to figure out what part is not working properly first.

Common Reasons Your Toilet is Running

  • Damaged seals
  • Gap in the flush valve
  • Small cuts on your flush valves
  • Fill valves that will not close


The good thing about your toilet is that all of these parts are affordable and easy to replace. Sometimes it is only necessary to change out one part, and you will immediately fix the problem.


One trouble you may run into is that you may replace the wrong part in hopes to fix a problem. This is simply a waste and then you might need to reinvestigate the reason for your trouble. Additionally, you may find that some of these parts are quickly worn away by different toilet cleaners. Although you would not think it, chlorine can be enough to wear down flappers.

Do I Have a Running Toilet or a Leaky Flapper?

When you have a running toilet it is actually considered to be a wide-open flapper. The causes of a running toilet may be because the flapper cannot close at all. This is due to the flush valve holding it open. This will allow water to constantly run from the tank to the bowl, and then down the drain. 


If you have a leaking flapper, this will be caused by your flapper simply getting old. Leaks can also be caused by small pieces getting into your tank and slopping the flapper and the flush valve. This causes the water in the tank to leak into the bowl. As compared to a running toilet, a leaking flapper can waste up to 200 gallons of water per day. This can end up increasing your water bill by up to $50 per month. 

How to Fix a Running Toilet

Sometimes the fix for a wide-open flapper (a runny toilet) can be extremely simple. All you need to do is jiggle the handle. If this does not work, you can also turn off the water, and turn it back on each time you need to flush it. Although these methods work, there is a bit of a better option to fully fix your running toilet.

Tools You Will Need

  • Hacksaw
  • Pliers
  • Fill valve (you may or may not need this depending on if it needs to be replaced)

Step 1: Test the Flapper

Begin by pushing down on the flapper. You can do this with a stick. Do this while you hear the water running, and listen for it to stop running when you press down.


If the water does stop when you push down, it means that your flapper is not sealing properly. You will need to replace it.

Step 2: Replace the Flapper

You will now need to check the fill tube length. Cut it back so it’s at least half an inch above the waterline.

  1. Begin by shutting off the water supply valve. You will be able to find this either under the toilet or turn off the main supply.
  2. Drain most of the water in the tank by flushing the toilet until there is no water left. Use a sponge or towel to clear out any remaining water.
  3. Unhook the flapper and take it out.
  4. When purchasing a flapper you want it to be an exact match for your toilet. If you cannot find this, then you can buy a universal flapper.
  5. You should install the new flapper according to the instructions on the package.
  6. Hook the flapper chain onto the flush lever arm. Make sure there is a bit of extra chain when the flapper closes.

Step 3: Check the Fill Valve for a Leak

Start by flushing the toilet to look for a fill valve leak. You can lift the toilet float arm while the tank is filling. If the water stops, then you know you have an issue.


To stop the tank from filling further than ½-1 inch below the top of the overflow pipe, you can bend or adjust it. If the fill valve still leaks, you will need to replace it.

Step 4: Remove and Replace Old Toilet Fill Valve

After once again turning off the water supply, fulling flushing the toilet, and removing any water from the tank, it is time to disconnect the water supply line. Unscrew the fill valve locknut and lift out the old fill valve to get it ready for the new one.

Step 5: Install the New Fill Valve

If you have recognized an issue with your fill valve, then you will need to replace it. Do this by inserting the new fill valve in to the tank. Follow the instruction sheet on the packaging. Tighten the locknut slightly tighter than what you would do with your hand (about a half turn).


When the fill valve is at its maximum height, the overflow pipe should not be higher than the critical level mark. If this is the case, then you will need to shorten the overflow pipe with a hacksaw. Make sure it is one inch lower than the critical level mark on the fill valve.

Step 5: Connect the Fill Tube

Take one end of the new fill tube. You will need to attach one end to the valve nipple, but the other end to the angle adapter (this should have come with your tube)

Put the angle adapter on the overflow pipe, and finish this by attaching the flapper chain to the flush lever. Then turn on the water and flush your toilet to test it.

Related Questions

Do smaller leaks waste less water?

Yes, if you have a slow leak from your running toilet, you may only waste up to 30 gallons per day. This is still a lot, bu it a lot less than 250!

How often should I replace my toilet?

Your toilet as a whole can last up to 50 years. Having said that, you may not want to keep your toilet for half of a century. Instead, 15-20 years is a good amount of time to keep a toilet, and you can replace your toilet seat every 5-8 years.