Toilet Making Loud Noise When Not in Use

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Homeowners seek to make their dwelling a peaceful oasis of comfort and serenity, yet the sound of an unexplained loud noise coming from the toilet while not in use can quickly shatter that bliss.

If you suddenly hear this type of racket emanating from your bathroom, you may question what could cause such a disturbance and how to resolve it.

While you may be tempted to call a plumber immediately, it’s essential first to understand the cause of the noise and what steps you can take to repair it yourself. We’ll discuss the reasons behind certain toilet noises and provide you with some tips on how to fix them.

Read on to learn more about what to do when you hear a loud noise coming from your toilet when it’s not in use.

Types of Toilet Noises

Swiss Madison Well Made Forever SM-1T254 St. Tropez One Piece Toilet, 26.6 x 15 x 31 inches, Glossy White

1. Banging Noises


Various things can cause loud banging noises, such as a worn-out fill valve, faulty flapper, or high water pressure in your supply line. When the tank refills and is suddenly cut off by the shutoff valve, it produces a thunderous sound known appropriately as a ‘water hammer.’

This ruckus can be annoying to anyone nearby. If you ignore it, it can cause damage to the pipes, leading to costly repairs.


Diminish the annoying sound by lowering your water pressure with the shut-off valve. This will give you more control over how much noise comes out of your pipes and make them less likely to cause unexpected noises.

Curing a noisy toilet can be simple or complex, depending on the issue’s root. If your outdated fill valve is causing it, replacing it should do the trick. 

2. Gurgling Noise


If your toilet is making a gurgling noise when not in use, the cause is likely due to a clog in the drainpipes. When you hear a gurgling sound after flushing the toilet, it could be due to air escaping from the drain line and entering the toilet.

This often indicates a blockage in either the vent stack or inside the toilet itself. It may even indicate that your sewer drain has broken down and requires immediate attention.


To address this issue, your drain lines should be expertly cleaned to eliminate any obstructions or blockages that are causing the gurgling noise. If it continues, you may need to consult a plumber to evaluate the pipes and determine what is going wrong.

3. Ghost Flushing


Are you hearing the sound of a toilet flushing when no one is in the bathroom? Don’t worry, it’s not an apparition, and your toilet may be “ghost-flushing.” This phenomenon occurs when the fill or flush valve fails to close entirely, and water continues running.  The water eventually builds up, which causes the toilet to flush itself.


First, remove the toilet lid and ensure the refill tube is above the overflow pipe. Look for any worn or faulty flappers, then examine the flush valve drain for any problems. If all of these components are functional, it’s time to call a professional plumber.

You’ll be relieved that ghostly noises don’t indicate supernatural activity but rather require attention to fix.

4. Hissing Sound


Are you familiar with that hissing sound emanating from your toilet? If so, it’s likely caused by a broken water-fill valve. This component regulates the amount of water going into the tank and when defective, can cause leakage resulting in this noise. 


The solution is to check the fill valve for any visible signs of damage. If it appears to be outdated or broken, you should replace it with a new one. If this does not resolve the hissing noise, then it might be time to contact a plumber for further advice and assistance. 

5. Vibrating Sound


Vibration is the fifth potential source of a loud rattling noise emanating from the toilet. This phenomenon could be caused by several factors, including a broken seal, an impaired water pipe, or even a worn-out washer.

In specific detail, it may originate from the diaphragm gasket inside the fill valve that has become rigid and lost its flexibility due to excessive wear.


To diagnose the issue, inspect the pipes around the toilet for any signs of damage or leaks. If none are present, replacing the wax seal around the toilet is next. Finally, if the issue persists, the washer may need to be replaced to stop the vibrating sound. 

6. Fill Valves

Fluidmaster 400A Anti-Siphon Universal Toilet Tank Fill Valve,Black


If you hear a loud noise from your toilet when it is not in use, the culprit may be a broken fill valve. Fill valves are responsible for controlling how much water enters the tank and, if malfunctioning or damaged, can cause an overflow resulting in big sound.


If the fill valve is broken, it must be replaced in order to fix the issue. Replacing the fill valve can be a relatively simple project for a qualified plumber, and it is an effective solution for the issue of a toilet making a loud noise when not in use.

7.  Floats

Danco 40121 Plastic Toilet Float, Black


The float is a small plastic ball attached to a rod inside the tank. Its purpose is to monitor and regulate the water level in the tank.

A faulty float can cause the tank to overfill, resulting in a loud noise when the toilet is not in use. If the float is too high, the water will run continuously until emptying the tank.


The solution is to adjust the float height. Lower it if it is too high by carefully bending the metal arm and vice versa. This should be done slowly and with care, as too drastic a change can cause the water to run continuously.

Frequently Asked Questions

Can a running toilet cause damage?

Yes, a running toilet can cause damage to your home and drain system if left unchecked. A continually running toilet wastes enormous amounts of water, which can result in expensive utility bills.

Additionally, a toilet that runs non-stop can cause pressure to build up within the pipes, potentially leading to flooding or water damage to your home.

How much does it cost to repair a running toilet?

Fixing a leaky toilet can be expensive, depending on the source of the issue. Replacing your flush valve alone could cost anywhere from $75 to $200. Other necessary repairs could amount to around $400 in total.

Before you take that route and break the bank, consider investing in some replacement parts like toilet flushing valves which are usually cheaper and range between only $10-$30 each.

Is it OK to put bleach in the toilet tank?

No, it is not advisable to put bleach in the toilet tank. Bleach should never be used with other household cleaners, particularly those that contain ammonia.

Adding bleach to the toilet tank can cause a dangerous reaction that releases toxic gases and fumes.


The probable source of a loud noise occurring from your toilet when not in use could be one of several factors. Fortunately, many are easy to remedy and shouldn’t take long for diagnosis or repair.

However, if no solution can be found, it may necessitate calling in an expert plumber or contractor. By taking the time to investigate and identify the cause, you will have an inexpensive resolution soon to keep unwanted noises at bay.

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