Toilet Makes Noise After Flushing: Common Causes and DIY Fixes

Since publishing my detailed guide on quiet flush toilets, I’ve had tons of emails from readers regarding different types of toilets sounds. Recently, one of my avid followers asked, “My Toilet Makes Noise After Flushing; what Should I Do?”

Well, as I’ve always done in the past, I’m going to answer her question in the form of a blog post.

But before we dive in further, if your toilet makes hissing sounds, kindly follow the link I’ve provided, as it could save you a lot in water bills.

The reason the toilet makes noise after flushing: foghorn sound. It’s most likely because it’s got a metallic ballcock fill valve. It could also be the washer in the assembly is worn out or loose.

There are other different types of sounds that you’ll hear after flushing the toilet, and they all have different causes.

In this guide, we shall be looking at the different types of noise a toilet makes after flushing and how to fix them.

Toilet Makes Noise After Flushing Causes?

When you flush a toilet, it can make loud and irregular sounds for a number of reasons. Sometimes you can hear something like a water splash, boiling water sounds or a slap kind of noise or even humming sounds.

In most cases, these sounds often indicate a problem with the toilet or the plumbing system. A water hammer, dirty valve, a faulty float switch could be the reason as to why your toilet is making these strange noises when you flush.

Therefore, it’s important to investigate the cause of these noises and have them fixed ASAP, so they don’t become a serious problem in the future. If a toilet makes noise after flushing, then below are some possible causes?

Water Hammer

Do you hear loud banging noises coming from your walls after flushing the toilet? If yes, then that’s what we call a water hammer.

While water hammers can cause major water damage, it’s so easy to fix. But below is a detailed guide to help you better understand this phenomenon.

Think of the water in your plumbing pipes as a long line of cars driving on the expressway. When the first car hits the emergency brakes, what happens next?

Well, the cars are likely to slam on each other- each car slamming on the one in front of it, causing a series of accidents.

The same happens when you flush your toilet.

After flushing the toilet, a valve is opened, allowing more water to collect into the toilet tank. The valve suddenly shuts off, causing the water that was rushing into the toilet tank to stop immediately. The pressure exerted by the water causes the pipes to produce a loud banging noise.

Water hammer consequences aren’t realized immediately. However, the force may eventually break or loosen the poorly soldered fittings and joints in the plumbing system, which could lead to expensive leaks in the walls.

To fix the problem, T-shaped air chambers are added to the water lines to serve as shock absorbers. But with time, the water can displace the air in the chambers resulting in banging sounds you hear.

For a home with T-shaped air chambers, you can solve the banging noise problem by:

·         Shutting off the water supply- shut off your water main.

·         Open all the faucets and let them drain

·         Make sure you flush all the toilets

·         Run the washing machine and dishwasher for a couple of minutes to drain them

·         After all, the water has been drained, turn on the water at your main supply.

Draining the plumbing system will get rid of the banging noises you hear when you flush the toilet. If the above process doesn’t solve the banging noises, it could be that:

·         Air chambers were never installed

·         Plumbing pipes have become loose from the support

·         The air chambers could be clogged

In such a case, you will need a professional plumber to help fix the problem for you.

Dirty Valve

A dirty valve is one of the most common reasons why your toilet is making a screaming foghorn noise.

However, you shouldn’t worry, as this is a simple fix that shouldn’t take more of your time. You need to shut off the water supply to the toilet- there’s a valve located to the hose that supplies water to the toilet tank.

Remove the cistern lid and locate the fill valve and remove any dirt, debris or water sediments from the valve. Allow water to flow out of the valve as this will help flush out any debris in the fill valve line.

Switch the supply water back on, and the noise should be gone. For more details on how to fix a blocked fill valve, check out the guide here.

Faulty Washer

Do you hear buzzing sounds when you flush your toilet? Does the noise sound similar to foghorn? The problem could be a broken float switch or a damaged washer. But how do you diagnose if the float switch is to blame?

Well, start by:

·         Opening the cistern and flushing the toilet.

·         After you start to hear a flushing noise, lift the float ball all the way up.

·         If the noise stops, then the problem is the washer- and it needs replacement.

To replace the washer, look for 3 screws located at the top of the toilet fill valve. If you can see the screws, then your toilet is not entirely sealed. Switch off the water supply and drain the toilet tank by flushing water down the drain.

Unscrew the screw from the fill valve and remove the ball and the flush valve top out of the tank.

Remove the washer from the bottom of the flush valve and replace it with a new washer. After replacing, put the toilet back and give flush the water again and see if you can still hear the buzzing sounds.

Ballcock Fill-Valve

If you have replaced the washer and still experience buzzing sounds after flushing, the next step would be to replace the fill valve.

Here’s what you should do:

Switch off the water supply and, flush the toilet, remove all the water from the cistern.

Disconnect the supply hose from the valve connector located under the tank and then loosen the valve locknut using adjustable pliers.

Successfully unscrew the nut and remove the old valve from the tank. Replace the old fill valve with a new fill valve, and then screw the locknut back tight.

Screw the water hose back and let the tank refill. You may need to adjust the float to bring the water level to an inch of the overflow tube.

Blocked Vent

Even though slight gurgling noise from your flush toilet is normal, a toilet that constantly gurgles after flushing is often an indicator of a blocked vent.

Some suction is created in the pipe after flushing, and the pressure caused by that suction is relieved by another that vents from the outside of the home.

If the vent pipe becomes blocked, it results from suctioning build-up through the piping system along with the water producing gurgling noise.

Unclogging the vent pipe will help solve this problem.

On Toilet Makes Noise After Flushing

There are different types of sounds that a toilet makes after flushing, and each sound is an indicator of a different problem.

Fixing buzzing, gurgling, foghorn sounds all require a different approach. Luckily above guide highlights the important steps that you should undertake to fix different sounds that a toilet makes after flushing.

Have any remarks? Kindly let me know in the comment section below.


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