[SOLVED] Toilet Flushes by Itself

It’s never a good thing when your toilet starts flushing by itself. You know it’s not supposed to do that – and it almost always means that something is wrong. But what could be causing your toilet to flush on its own?

It might be something as simple as a loose lift chain, or it could be something more serious like a damaged toilet tank.

No matter what the cause, it’s important to get it fixed as soon as possible.

So let’s take a look at some of the most common causes of toilets flushing on their own, and how you can go about fixing them.

Fixing Toilet that Flushes by Itself

If you are experiencing phantom flush aka ghost flushing, here are some of the reasons why your toilet may flush by itself and their appropriate solutions:

A Faulty or Failing Flapper Seal

The number one major cause of ghost flushing is a faulty or failing flapper seal. The flapper seal is an important part of the flush valve mechanism. It’s a flexible rubber that prevents the water in the toilet tank from escaping into the toilet bowl.

When you push down the flush lever (or flush button), it pulls up the flapper seal, discharging water into the toilet bowl to flush the toilet. However, the flapper seal is fragile and can fail or become faulty over time.

A failed or faulty flapper seal will no longer keep water within the toilet tank.

Instead, the water within the toilet tank will run or leak continuously into the toilet bowl – a phenomenon known as ghost flushing.

A flapper seal is faulty and/or will fail if it’s clogged, worn-out, hardened, warped, or has a slack or overtightened lift chain.

A Clogged Flapper Seal

Over time, the mineral deposits in a hard water supply or debris/sediments in the toilet tank can build up on the flapper seal and clog it.

This will prevent the flapper seal from sitting properly and creating a perfect seal in the flush valve mechanism. Hence, water will leak from the toilet tank through the poor seal into the toilet bowl – ghost flushing.

A Worn-Out, Hardened, or Warped Flapper Seal

Most flapper seals are made of rubber though there are some metallic flapper seals. Rubber flapper seals tend to wear out, become hardened, or warped while metallic flapper seals tend to deteriorate and rust over time.

Such a damaged flapper seal will not fit the flush valve opening perfectly and this will cause water to escape into the toilet bowl from the tank.

A Slack or Overtightened Lift Chain

A lift chain connects the flush lever to the flapper seal (or flush valve). If the lift chain is slack, it can either get stuck to other parts in the tank or get under the flapper seal. Either way, it’ll cause the flapper seal to fail.

On the other hand, if the lift chain is overtightened, it’ll slightly unseat the flapper seal, preventing it from making a good seal on the flush valve. Either a slack or overtightened lift chain will cause our toilet to flush by itself.

If you’re using a toilet with a flush button, the connecting rod may be too long, and pressing down the inner flush button.

Solutions to a Faulty or Failing Flapper Seal

Luckily, all of the reasons for a faulty or failing flapper seal above have solutions. If your toilet flushes by itself because of a faulty or failing flapper seal, try any or all of the solutions below:

Removing Clogs from a Flapper Seal

1. Stop the water supply to your toilet tank by shutting the water supply valve.
2. Flush the toilet to remove water from the toilet tank. You may need to hold down the flush lever/button to remove excess water in the toilet tank.
3. Remove the tank lid and keep it safe.
4. Carefully disconnect the flapper seal from the overflow tube.
5. Pull the lift chain to pull out the flapper seal. You may not need to disconnect the flapper seal from the lift chain except if necessary.
6. Check out for clogs on and/or under/around the flapper seal.
7. Check out for clogs around the flush valve opening.
8. Remove any clogs you find with a brush/sponge and vinegar.
9. Place the flapper seal back into the toilet tank and reconnect it to the overflow tube.
10. Open the water supply valve and let the water fill the toilet tank.
11. Check to see if the flapper seal now closes properly and listen carefully for any incidence of ghost flushing.
12. Replace the toilet lid and push the flush lever/button to flush your toilet, allow the toilet tank to refill, and listen again.

Fixing a Worn-Out, Hardened, or Warped Flapper Seal

1. Follow the first three steps in the solution above.
2. Carefully check the flapper seal to see how it fits the flush valve opening.
3. Gently pull and release the lift chain as you examine whether the flapper seal is worn out.
4. Disconnect the flapper seal from the overflow tube and examine it with your hand if it’s hardened or deformed. Look out for rust on a metallic flapper seal.
5. If the flapper seal is worn-out, hardened, or warped, it needs a replacement. That’s the only solution. Make sure that you get the right replacement flapper seal for your toilet model.
6. Disconnect the old flapper seal from the lift chain and connect the new flapper seal.
7. Connect the new flapper seal to the overflow tube and check how it fits into the flush opening.

After that, follow the last three steps from the solutions we have discussed earlier. That are-

1. Open the water supply valve and let the water fill the toilet tank.
2. Check to see if the flapper seal now closes properly and listen carefully for any incidence of ghost flushing.
3. Replace the toilet lid and push the flush lever/button to flush your toilet, allow the toilet tank to refill, and listen again.

These steps should fix the issue except you didn’t get something right.

Fixing a Slack or Overtightened Lift Chain

1. Follow the first three steps in the first solution above.
2. Carefully check the flapper seal and the lift chain. Does the lift chain look too slack or overtightened?
3. If the lift chain is slack or overtightened, adjust it appropriately by shortening the chain or connecting it to the right hole on the flush lever. The lift chain should only be a quarter-inch slack.
4. If necessary, disconnect the flapper seal and lift chain before adjusting the lift chain.

Finish up the process by following the last four steps in the first solution above-

1. Place the flapper seal back into the toilet tank and reconnect it to the overflow tube.
2. Open the water supply valve and let the water fill the toilet tank.
3. Check to see if the flapper seal now closes properly and listen carefully for any incidence of ghost flushing.
4. Replace the toilet lid and push the flush lever/button to flush your toilet, allow the toilet tank to refill, and listen again.

If the flapper seal doesn’t close properly after flush even after adjusting the lift chain, you may need to change the lift chain altogether.

Other Possible Reason Why Toilet Flushes by Itself

Although a faulty or failing flapper seal is the main reason why your toilet will flush by itself, it’s not always the only reason. Another reason is a bad or poorly adjusted toilet float.

A Bad or Poorly Adjusted Toilet Float

The toilet float (ball, cylinder, or cup) is meant to stop the inflow of water into the toilet tank once the water in the tank has reached its expected height.

However, if the toilet float or float arm is bad, it’ll either get hardened or stuck and will no longer gauge the water level in the toilet tank correctly. In such a case, the toilet tank will either be filled incompletely or overflow.

When the toilet tank overflows, excess water will flow into the overflow tube and into the toilet bowl, causing the toilet to flush by itself.

Also, the toilet float has an adjustment bolt for adjusting the height of the toilet float to properly set the water level in the toilet. If the adjustment bolt is poorly adjusted to allow excess water into the toilet tank (set too high), the toilet tank will overflow and ghost flushing will occur.

Replacing or adjusting the toilet float can stop the toilet from flushing itself.

Fixing a Bad or Poorly Adjusted Toilet Float

Follow the first three steps in the first solution above. That are-

1. Stop the water supply to your toilet tank by shutting the water supply valve.
2. Flush the toilet to remove water from the toilet tank. You may need to hold down the flush lever/button to remove excess water in the toilet tank.
3. Remove the tank lid and keep it safe.

Normally, the toilet float should rest back (or lower) into an empty toilet tank. If it’s not resting back, the toilet float is hardened or got stuck. Examine the float with your hand to see the actual reason. While a stuck float can sometimes be fixed, almost all hardened float requires replacement. So, buy one and continue the process as laid down below.

1. Remove the toilet float by unscrewing the hinge pin or nut holding it in place.
2. Install the new one by screwing it in the old one’s place.
3. Now, open the water valve and refill the tank.
4. Examine the water level before the toilet float stops water from entering the toilet tank.
5. If the water overflows, you need to adjust the toilet float by turning the plastic screw counterclockwise to lower the water level.
6. Stop when the water level is just about a half inch to the tip of the overflow tube.
7. Replace the lid, flush your toilet, and allow the toilet tank to refill itself.
8. Listen carefully for any sound of ghost flushing.

Conclusion

Toilet ghost flushing or a toilet that flushes by itself is an annoying issue. But, with the two solutions discussed above you can easily fix it and stop it from occurring again in the future.

If after following all of these steps your toilet continues to flush by itself, then you may need to call a professional plumber to inspect it and fix the issue.

Don’t forget to check your toilet warranty as they may provide you with free or discounted services.