Toilet Leaking Sound (Causes & Fixes)

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Hearing a leaking sound from your toilet can be caused by many things, some of which result in a waste of water and higher utility bills. Identifying the reasons is crucial for fixing the problem.

Leaking Toilet Sound Video

Both you, and your tenants need to know that this little innocent sound means that you’re literally flushing money down the drain. 😭

In addition to wasting hundreds of gallons of water, one toilet with a minor leak can cost you $3-5 a day or $100-$150 a month. One toilet with a major leak can be $10-$20 a day or $300-600 a month. 💸🤢

Tell your tenants, if they hear this sound and can’t find an immediate fix, to give you call so you can reach out to us or your local commercial plumber to come out and quickly fix the problem. 🛠️👍

Download our FREE Property Manager Survival Guide in our bio to help you save your property from expensive repairs ✅

Why Does My Toilet Sound Like Water Is Running?

Faulty Flapper

At the bottom of the toilet tank, there’s a flapper, which is a rubber wall that lifts to let water flow into the bowl when you flush it. If it is worn out or fails to seal correctly, water can continuously leak into the bowl. 

Fill Valve & Overflow Tube

A poorly adjusted fill valve results in a water level being too high in the tank. The water then spills over into the overflow tube, and you hear a leaky toilet sound.

Leaky Tank-Bowl Gasket

The gasket between the toilet tank and the bowl can wear out over time, which often causes a leaky sound.

Loose or Worn-Out Washers

Washers in the toilet’s assembly can become loose or worn out, causing water to leak and make noise.

How Do You Fix a Leaking Toilet Noise?

Replacing the Flapper

First, lift the toilet tank lid and check the flapper. If it looks worn out or is not sealing properly, it’s likely the source of the leak. To confirm this, do a dye test. For this, simply put a few drops of any food coloring in the tank and see if the color becomes visible in the bowl without flushing.

If so, the flapper is faulty. Turn off the water, flush the toilet to empty its tank, and replace the old flapper with a new one. Make sure it forms a tight seal.

Adjusting or Replacing the Fill Valve

Observe the fill valve while the tank refills. If water still flows into the overflow tube after the tank is full, the fill valve might need adjustment or replacement.

If the fill valve is the source of the problem, adjust the float to ensure the water stops at the correct level. In case the adjustment doesn’t help, consider replacing the fill valve.

Adjusting the Float

Ensure the water level is below the top of the overflow tube. If it’s too high, adjust the fill valve float to lower the water level. To do this, bend the arm downward (for older ballcock valves) or by changing the screw on the float cup (for newer fill valves).

Replacing the Tank-Bowl Gasket

Look for water leakage around the base of the tank where it meets the bowl. If you see any, the gasket might need to be replaced. 

Turn off the water supply, flush the tank to empty it, and carefully remove the gasket from the bowl. Replace the old gasket with a new one and reassemble the toilet.

Replacing Washers

Check for any loose washers and tighten them. If they are worn out, replace them, but this might involve disassembling parts of the toilet. So, refer to the manufacturer’s instructions or seek professional help if needed.

Preventive Measures

  • Regular inspections to check toilet parts for wear and replace them as soon as possible.
  • Always use high-quality parts when fixing a leaky toilet to make sure the plumbing lasts longer.
  • Routinely clean the flapper and the fill valve to keep your toilet working smoothly.


Knowing the real cause of the toilet leaking sound can help you fix the issue without spending too much on parts that were never needed.

If you’ve tried the above solutions and the problem is still there, it may be time to call a professional plumber. Persistent leaks can indicate more complex issues that require expert diagnosis and repair.