3 Causes | Why does my toilet randomly run for few seconds?

If you’re a homeowner, there’s a good chance that, at some point, you’ve had to deal with a toilet that runs on its own. This can be annoying and costly since it can waste water and increase your utility bill. 

Today, I’ll explain why your toilet randomly runs for a few seconds on its own and offer some tips for solving the problem. We hope this information is helpful!

Why does my toilet randomly run for a few seconds?

There are three potential reasons your toilet might be randomly running for a few seconds. 

Cause1. Toilet periodically runs for a few seconds Due to the Flapper

Defect flapper is the main reason for toilet occasionally run. It is mainly seen in new toilets. After each flush, the flapper valve, which controls the flow of water into and out of your tank, maybe worn out and not sealing properly.

This can cause the tank to constantly refill, which will, in turn, cause the toilet to run. Replacing the flapper may fix the issue. I will discuss this later.

Cause2. The new toilet randomly runs for a few seconds because the tank’s water level is high.

After installing the toilet, the tank’s water level is very important because too high causes overflow and too low causes not enough water.

If your toilet is new, mainly for this reason toilet runs randomly. The water level is high as per its requirements. So after the tank is filled with water, extra water flows into the overflow tube to prevent overflowing.

Adjusting the height of the water may fix your new toilet that runs occasionally.

Cause3. Why does my toilet just randomly start running- Plumbing Leakage.

Another option is that there may be a leak somewhere in the plumbing system, which is causing water to flow continuously into the toilet tank and forcing it to run every 5 minutes.

plumbing leakage can cause a toilet to random flush

How do you fix a toilet that runs randomly?

1st Adjust Water Level

Your toilet’s running problem may be worth checking to see if the water level in your tank is set too high. If the water level is too elevated, the excess water will flow into the bowl each time the toilet is flushed, which will cause it to run.

Adjusting Water Level in two ways; one is ballcock or floating arm adjustment. The second one is to increase overflow tube height.

Ballcock or floating bulb 

The floating ball is responsible for water height; if it’s too down, the water level is low; if it’s high, the water level is also high, which causes the running toilet.

It is simple to adjust; you just need to slightly bend it low by carving the metal arm.

If the toilet is modern, a floating cup is present on top of the refill valve. The need to lose by half a knot. After doing this, flush once and then check the water level.

Now move to the overflow tube. 

It is a wide hollow tube placed over the flapper. If it’s too short, every time the tank is filled with water goes down by it.

Increase the height. Note that the toilet tank’s water level should always be below 1/2 inch of the overflow tube, and the overflow tube top should be 1 inch below the edge of the tank.

After adjusting the water level and you get the same result, you need to change the flapper. The seal is broken.

How to change the Flapper

The flapper is made of rubber which is responsible for sealing the water from the tank to the below. The flush button opens up when we need a push or pull, and water runs through below to clear the waste.


1. Turn off the water supply to the tank, and flush the toilet.

2. Pull out the flapper and replace it with the new one.

3. While pulling out the flapper, you need to disconnect the attached flush chain; after replacing it, connect with it.

4. Ensure the chain hook is tucked correctly; otherwise, the seal is not open if it is too loose or the flapper won’t close.

5. Connect the water supply and inspect proper flushing or not.

Read more- the toilet randomly runs after replacing the flapper.

Is a running toilet an emergency?

A running toilet is not typically considered an emergency. Still, it can certainly become one if it is not fixed on time. 

A running toilet can waste a lot of water, which can cause your water bill to increase. It can also cause damage to your plumbing system, resulting in expensive repairs. 

If you are experiencing a running toilet, fix it as soon as possible.

What can you do if your toilet is running?

If your toilet is running, there are a few things that you can do to try to fix it. 

First, inspect the water level in the tank and make sure that it is set at the correct level. If the water level is too low, it can cause the toilet to run. 

You can also try to adjust the flapper valve or the fill valve to fix the problem. 

If these fixes do not work, you may need to call a plumber to help you get your toilet running properly again.

Wrap Up on My Toilet Randomly run For a few Minutes 

The mystery of the randomly running toilet has been solved! Although it was initially believed to be a plumbing issue, it turns out that the culprit was actually a moth. 

Thankfully, this problem can easily be fixed by changing the flapper or adjusting the water height in the toilet tank. Have you ever had a random toilet run? If so, what did you do to fix it?


Q1. Can a running toilet cause a leak?

A running toilet can definitely cause a leak, and it’s essential to fix the issue as soon as possible. A leaking toilet can waste a lot of water while also causing other plumbing issues in your home.

Q2. Can a running toilet run a well dry?

That’s a question that likely has many homeowners wondering, and the answer is, unfortunately, YES. A running toilet can use up to 200 gallons of water per day, which means it can easily deplete a well or water tank. 

If you’re noticing your water levels dropping quickly, it might be time to invest in a new toilet or find a way to fix the one you have. 
Running toilets can be caused by various problems, so it’s important to troubleshoot and identify the source of the issue before taking any action. 

All that’s needed is a simple adjustment or repair to get things running smoothly again. 

As long as you’re proactive about addressing any issues with your toilet, you can avoid running into any significant problems down the road.

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