Does Your Toilet Flush on Its Own? Fix the Ghost Flushing

Last Updated on August 6, 2023 by toilethaven

Why Does My Toilet Keep Flushing By Itself?

So you are home alone in the middle of the night trying to get some sleep then your toilet flushes! No need to scream or call 911. Your toilet is ghost flushing which is also known as phantom flushing. This has nothing to do with ghosts. It describes a condition where a toilet randomly flushes on its own.

A toilet flushing on its own, also known as ghost flushing, happens when water leaks from the tank to the bowl, usually due to a worn-out/warped/dirty toilet flapper. When the water level in the tank gets too low, the float triggers the fill valve to start refilling the tank.

As I have mentioned, most of the time, ghost flushing is caused by a worn-out/warped/dirty toilet flapper, but it can also be caused by other problems like a leaking flush valve seal, leaking tank bolts, or even a cracked tank. If there is water on the floor, it is an external leak, but if there is no water, it is an internal leak.

A toilet tank is designed to hold a constant amount of water. The fill valve, responsible for refilling the tank, is connected to the toilet float. The toilet float controls the opening and closing of the fill valve and, therefore, the water level in the tank.

Whenever the water level in the tank has dropped below a specific point, the toilet float moves down, opening the fill valve, which refills the tank. This gives the impression of a toilet that is flushing by itself.

What Causes a Toilet to Flush By Itself?


1. A bad toilet flapper

A toilet flapper is the rubber seal at the bottom of the toilet tank. It sits on the flush valve opening to ensure water does not flow down to the bowl unless during flushing. It is connected to the toilet flush handle arm by a lift chain.

When you push the flushing handle down, the lift chain, which was until that moment slack, gets some tension and lifts off the flapper allowing water to leave the tank and flow to the bowl via the flush valve.

If the lift chain is too tight, it will slightly unseat the flapper causing water to slowly escape to the bowl, causing the toilet to flush on its own.

Hard water causes the flapper to warp and therefore compromise its integrity. Mineral deposits or debris could also be trapped under the flapper, inhibiting effective sealing. As a result, water will keep seeping under the flapper and cause ghost flushing.

2. The Flush Valve

The flush valve is the opening through which water leaves the tank and enters the bowl. Although not often, the flush valve could crack and slowly leak water into the bowl. After some time, the water level in the tank will get too low, causing the toilet to flush on its own.

3. Leaking toilet tank

This mostly happens at the toilet tank bolts. The toilet tank bolts use a rubber washer to make a water-tight seal. Like the flapper, the rubber washers become worn out with time resulting in a leaking toilet tank.

If, unfortunately, your toilet tank has a small crack, it will be an expensive repair for you since porcelain will always need to be replaced.

With a leaking toilet tank, you will notice water pooling around the toilet’s base.

4. Leaking Water Supply Line

A toilet water supply line is a flexible line connected from the shut-off valve (back of the toilet) to the toilet tank.

Sometimes the coupling connecting the line to the tank will be dripping water on the flow, gradually reducing the amount of water in the tank. When too much water has been lost, the fill valve will start to refill the tank to compensate for the lost water.

5. Refill Tube is too Long

The refill tube is a narrow piece of tube that is connected from the fill valve to the overflow tube. During a refill, the refill tube sends a small amount of water back to the bowl.

If the refill tube is too deep inside the overflow tube, it will cause a siphon effect, forcing the fill valve to fill the tank after a few minutes.

How to Fix a Toilet That Flushes By Itself


Since a ghost/phantom flushing toilet is not caused by one defective part, the first thing to do is identify the problem’s source.

Check on the bathroom floor to check if there is any water. If you have water, it means you have a leaking toilet or water supply line.

If your floor is dry, you have an internal leak. To be sure of this, most people put food color in the tank and wait for 30 minutes. If you see the color appear in the bowl, it is most likely your flapper leaking. It could also be your flush valve.

1. Fix the Toilet Flapper

Since this is the main culprit, we will start with it.

  • Turn off the water supply to the toilet. The shut-off valve is located on the wall behind the toilet.
  • Flush the toilet and hold the handle down to remove as much water as possible.
  • Lift off the toilet tank lid. Place it in a safe place where it cannot fall off and break.
  • Check the condition of the lift chain. Is it too tight? Is it slightly unseating the flapper?
  • If the chain looks tight, increase its length a little. It should have a ½ inch slack when the handle is not operated. Do not, however, make too slack. If it’s too loose, it cannot lift the flapper up, resulting in a slow and ineffective flush.
  • Disconnect the lift chain from the flush handle arm.
  • Unhook the toilet flapper ears from the flush valve pegs.
  • Remove the flapper and keenly inspect it.
  • If the flapper looks warped and old, you must replace it.
  • If it looks to be in good condition but is full of dirt and mineral deposits, you can reuse it. Clean it wist water and a soft cloth in a sink till it’s sparkling clean. Use a cloth also to clean the top of the flush valve where the flapper sits. Put the flapper in position and connect the lift chain to the handle arm.
  • If the flapper is warped, then you have to replace it. Most toilet flappers are universal, and you will only need to buy the correct size according to your flush valve.
  • Install the new flapper and adjust the length of the lift chain. You might have to do this a few times to get it right.
  • Put the toilet tank lid back on and turn on the water.
  • Repeat the food color test to be sure the problem is fixed.

If the flapper was the reason why your toilet was flushing all by itself, then this repair should be enough to fix it permanently.

2. Clip the Refill Tube on The Overflow Tube

The refill tube should be clipped on the overflow tube but not be inserted to dip inside. Due to the fact that toilet tanks have different heights, toilet parts manufacturers manufacture them long.

What you should do after buying one is to cut it into an appropriate size according to your toilet tank height, and after that, clip it on top of the overflow tube.

3. Replace the Flush valve

If, even after replacing the toilet flapper, your toilet is still flushing on its own, or you have noticed a crack on the flush valve, you will need to replace the flush valve.

Replacing a flush valve takes more time since you must remove the toilet tank and install it back. It is always advisable to take that opportunity to replace the toilet tank with a bowl gasket and toilet tank bolts.

You can also go the extra mile and buy the complete toilet tank repair kit, including the fill valve, toilet float, and flapper. This is a detailed guide on how to replace a flush valve.

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4. Fix a Leaking Tank

If your toilet tank leaks, it will most likely leak at the tank bolts. Use an adjustable wrench or a combination of a wrench and a long screwdriver to tighten the bolts. Sometimes this can stop the leak.

If the bolts are corroded, and the rubber washers are worn out, you will need to replace them with new ones. Replacing toilet tank bolts means removing the tank and reinstalling it later.

Again, while replacing toilet tank bolts, you should also take the chance to replace the tank to bowl gasket. They are sold as complete kits and are inexpensive.

Here is a guide on how to replace toilet tank bolts. If the tank is cracked, you will need to buy a new one. Make sure you buy the same model or another model compatible with your bowl.

5. Replace the Water Supply Line

If the water supply line leaks, then that will be an easy and inexpensive repair for you. Turn off the water, flush the toilet, and remove the leaking line.

As you install the new one, do not use a wrench to tighten the plastic coupling that connects it to the tank. This can make it to an oval and start leaking immediately. It should only be hand-tight.


A toilet that flushes on its own wastes a lot of water, and the faster you fix it, the more water you save and the less the inconveniences. As we have seen, fixing a ghost-flushing toilet is something you can do comfortably on your own.

If you are unsure you can do it on your own, you can always call a professional plumber or a handyperson to do it for you.