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Explained: Three Strange Sounds Your Toilet Makes


You’re familiar with the sounds your toilet makes -- so familiar that anything out of the ordinary may be cause for concern.

Here are three toilet noises to keep an ear out for and what they could mean.


The brief hissing that accompanies your tank refilling is perfectly normal. However, persistent hissing is a sign one of these two problems:

Malfunctioning flap: Lift the lid and examine the flap on the bottom of the tank. If it appears cracked or brittle, you likely found your culprit. The deteriorated flapper isn’t creating a seal, allowing water to slip past into the bowl. This causes the tank to refill continuously. It’s an audible nuisance and a waste of water.

Replacing the flapper is an easy DIY job. Just follow the instructions on the package.

Faulty float: The float is the mechanism that raises and lowers with the water level in the tank. If it rises higher than the overflow tube, excess water will spill down into the tube, prompting a continuous refill.

To adjust the fill height, press the clip on the side of the float to move it down the rod. Position the float an inch or two below the top of the overflow tube. Then flush the toilet to see if the float stops below at the adjusted level. If that doesn’t do it, call a plumber.

Gurgling or bubbling

This could indicate negative air pressure within the drain line. When this pressure releases, water in the toilet bowl will bubble.

A clog in the main sewer line, such as a root obstruction, can create this sort of airlock.

In severe cases, dirty water will back up into your sink or bathtub.

Get this fixed by a plumber ASAP!


Older toilets have a float the resembles a small, black balloon. This a ballcock-style fill valve, and you may have a loose washer inside the mechanism. It’s nothing detrimental -- just super annoying.

To determine if this is the case, lift the tank lid and flush the toilet while holding up the float. If the sound is gone, you’ve found your problem. If you’re handy, you can disassemble the fill valve to replace the washer inside, or you can replace the entire fill valve.

If you run into any complications, contact Mallick Plumbing & Heating at (301) 804-6759.

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