What It Means When the Toilet Keeps Making Noise

It can be disconcerting when your toilet is making loud noises, especially if it is one you have not encountered before. But knowing when a toilet noise warrants a call to the plumber can be frustrating and stressful. Here, we break down some common toilet noises to help you diagnose any plumbing issues you may be having. If you need immediate help, please give us a call at 602-787-3956.

From a simple running toilet (most often cured by a simple valve replacement) to a toilet overflow or more complex problems like water leaks, there are many things that can go wrong with your toilet. When the toilet keeps making noise is the first indication that something is wrong. If your toilet keeps making noise when it’s being flushed or when it’s not in use, there are a variety of possible causes. Donley’s plumbing professionals diagnose common toilet noises, and the plumbing problems each sound can indicate.

Toilet Keeps Making Noise: 

A noisy toilet can have several causes, but the most common culprits are:

  • Leaking toilet valve
  • Malfunctioning fill valve
  • Calcium buildup inside the pipes

Checking the condition and position of the toilet valves should be your first step. If the valves are worn or brittle, replacing them should solve your toilet noise problem. If it doesn’t, call a plumbing professional.




Water hammer (also known as water knock) is a pretty frequent toilet noise complaint, and can even occur in other parts of your plumbing as well. According to a New York Times article, the loud noise described as water hammer occurs because:

“Water is not compressible, so when the flow inside a pipe is suddenly slammed to a stop while it is running rapidly – like when a washing machine valve snaps off or a faucet is closed quickly – the momentum of the water causes it to slam forward and bang around against the sides of the pipe and the inside of the fittings. This causes the hammering sound. In addition, it can cause the pipes to chatter and vibrate.”

If you find that after flushing, there is a loud hammering toilet noise, it may be that it is the sudden stopping of the water flow as described above. Try reducing the flow of water to the toilet making noise by adjusting the shut-off valve. If that does not work, consider installing a regulated fill valve. This will reduce the pressure of the water filling your toilet tank.



If you notice that after you flush your toilet is making a high-pitched noise as the toilet’s tank is refilling, do not panic. The most likely culprit is the ballcock valve (also known as a float valve). Luckily, this is an extremely simple and cheap fix. In fact, although the issue can sometimes be resolved by adjusting the existing ballcock mechanism because the parts are so cheap, many people go ahead and replace the whole thing since they are dismantling it anyway. Enterprising homeowners may choose to make this replacement themselves. If you are not comfortable or do not have the time, a qualified plumber should be able to make the repair quickly, getting rid of this funky toilet noise in virtually no time at all. Furthermore, this problem happens a lot more frequently with toilet ballcock systems. Upgrading to a fill valve while you are at it may spare you from having to undergo the exercise again so soon in the future.

Toilet Whistles When Flushed:


A toilet making an air noise or a whistling or hissing sound is a sign that the fill valve is not closing and sealing properly, and air or water is leaking from the fill valve. If the fill valve isn’t closing properly, begin by replacing it. If this doesn’t solve your problem, call a plumbing professional.



This toilet noise almost always happens in the middle of the night, and especially after watching a scary movie … Your toilet suddenly seems to flush on its own. Have no fear! What is actually probably happening is that the water in your toilet tank is slowly seeping out, probably through a faulty flapper. Once the float gets below a certain level, the water switches on and voila, the toilet seems to magically flush on its own.

To determine whether or not the flapper really is the culprit, put some food dye in the toilet tank. Wait for about 30 minutes and then look to see if any of the food coloring has traveled into the bowl. If so, you have caught your ghost, so to speak. Luckily, replacing the toilet flapper is another quick and easy job that you can tackle yourself or count on a plumber to complete for an incredibly reasonable price.



Hissing is another common toilet noise complaint that can often be chalked up to a deteriorating flapper. Alternatively, it can also be caused by water draining into the overflow tube. You see, when the toilet tank fills to its appropriate level, the fill valve or toilet ballcock stops it from running. If the fill valve or toilet ballcock are not adjusted to the appropriate level, water then begins filling into the overflow valve. By making sure the fill valve or toilet ballcock are set to a level below the overflow valve, this problem can be easily rectified.



A toilet making a gurgling noise is among the most perplexing toilet noises because its source is not so easily traced. A gurgling toilet could be the result of a blocked sewer drain, blockage in a vent stack or a blockage in the toilet itself. If you find that your toilet is making a gurgling noise, it is one issue that is best not tackled on your own, unless you are a plumber yourself (in which case, we are flattered that you are reading our article). Avoid using that toilet if possible and call a professional ASAP to make sure that that annoying toilet noise does not turn into a full-fledged plumbing nightmare.

Toilet Noise After Flushing:


Depending on the type of noise, a toilet that makes noise after flushing or filling can indicate a leak in the system, a buildup of calcium or other debris in your pipes, or the need to replace the toilet altogether. If the solution to your toilet noise problem isn’t listed here, give Donley Service Center a call for help.

Toilet Makes Loud Noise Randomly


If you notice your toilet making a loud noise, either when flushed or randomly, it’s a clear indicator that something is wrong with your toilet. The problem is most likely a loose washer in the ballcock assembly, which is common among older toilets with a metal ballcock-style fill valve. Tighten or replace the washer and fill valve assembly. If this doesn’t solve the noise problem, call Donley Service Center for help.

Toilet Making Noise When Not In Use


If your toilet is making noise when not in use, a worn or faulty flapper is likely the reason. If the flapper is not working properly, it can cause your toilet to constantly run, make noise, and ultimately, increase your water bill. Replace the flapper. If this doesn’t solve the noise problem, it may be time to replace your toilet. Call a plumbing professional.

Is your toilet making loud noises that we did not outline in this article? Or did you find the problem and are ready to have one of our plumbers come out and fix it for you? Either way, feel free to give us a call at 602-787-3956 or use our online form to schedule a same-day service to tackle any and all of your plumbing needs.