Toilet Hissing: Is That Sound Normal?


A hissing toilet is a common phenomenon that can be seen in most households. The sound of toilet hissing can sometimes be loud and troublesome. You may feel like a reptile has invaded your bathroom space. The problem of hissing toilet may remain for a long period of time, which can ultimately irritate you on a regular basis.

However, here is good news for you, toilet hissing noise can be resolved easily once you understand the reason behind it. If the weird and spooky sound from your toilet is annoying you, consider this article as help at hand. In the further parts of the article, you will read about its pattern and the ways to fix it.

Why Does a Toilet Hiss?

The most common problem with the toilets is the hissing sound. When the toilet in your bathroom hisses, the first question that might arise in your mind is – “Why Does a Toilet Hiss”? Well, if you are hunting for an answer to this question, then we are here with an answer!

The common reason why the toilet produces a hissing sound is that air or water is moving through your water line into the toilet tank. Let’s discuss water first, as it is usually a quick fix once you locate the problem. Toilets have a refill valve that controls how much water hoes back into the tank when you flush.

If the refill valve is not working perfectly, you will end up with too much or too little water after each flush. A hissing sound means that the refill valve is still allowing a little bit of water into the tank because it has not shut off like it is actually designed to.

So, when you hear your toilet hissing, take the lid off your toilet tank immediately. The first thing to check now is to see if the water is running down the overflow pipe. If it is, then your refill valve is not shutting off when the tank is full. This means that the water is continuously going down the refill tank and running up your water bill.

If the water level looks perfectly fine and you still hear the hissing sound, the issue could be with the water supply to your toilet, an issue further back in the plumbing, or even the presence of air in the system. A professional plumber must timely investigate all these problems because the toilet hissing could mean a leak inside an interior wall, which could further damage your home.

Toilet Hisses Randomly Every Few Minutes

If you happen to notice your toilet making a weird noise randomly, it is a clear sign that something is wrong with your toilet. This problem can most likely occur due to a loose washer in the ball cock unit. It is common in old constructed toilets that have a metal ball cock style fill valve. You can try to fix the issue of the toilet hissing randomly every few minutes by tightening or replacing the washer and fill valve assembly.

Toilet Hissing Constantly

If you are noticing the toilet hissing constantly, then the problem might be related to the inter water valve of the toilet. Over a period of time and usage, sometimes bits of sediment or hard water may get deposit in the valve. It ends up partially blocking water flow into the tank. It leads to an increase in water pressure in the valve, which ultimately forces the water out in a narrow stream, due to which a hissing sound constantly comes in the toilet. 

Toilet Hissing and Not Flushing

It is common for a commode to make noises when it flushes. However, the toilet should be quiet the rest of the time when a person is not using it. So, if your toilet hisses when it is supposed to be quiet, it could be a direct sign of a plumbing problem. Toilet hissing and not flushing can occur due to the flapper chain. Check if it is too tight because it may prevent the valve from shutting the way. You can try jiggling the chain to determine if it has slack. If the flapper chain is tight, make sure to lose it.

The Toilet is Hissing and Leaking

Sometimes toilets make strange noises like gurgling, screaming, hissing, etc. These noises are mostly related to the movement of air or water. If the toilet hisses, it is probably because water or air is leaking from the fill valve. In any case, if the valve is not shutting properly, the toilet may leak. Now, let’s discuss how you can fix the problem of hissing in your toilet.

How to Stop the Toilet from Hissing?

If your toilet is hissing and you are finding out ways to stop it, then we are here with some effective ways to help you stop the toilet from hissing.

The hissing sound is most likely due to a defective refill valve. There are basically two valves inside the toilet tank, i.e., a flapper valve. Located at the bottom of the tank and the other is a refill valve that automatically refills the tank each and every time the toilet is flushed. So, to replace the valve, turn off the water supply to the toilet. Flush the toilet properly to drain the tank and then remove the excess water with a sponge.

Under the outside of the tank, you will find a large metal nut that secures the water supply pipe to the toilet. Simply remove the nut. There will be a second nut as well that secures the refill tower to the tank. You need to remove the second nut and the refill tower. Now, reinstall the refill tower and flapper valve and reconnect the water supply pipe. You can then switch on the water supply but make sure to do this slow and check for leaks.

Another quick repair to consider is replacing the two washers and screws that secure the tank to the bowl. With time, the washers will fail, and the tank will start to leak; therefore, replacing these is preventive maintenance.

Let White’s Plumbing Help You!

If your toilet makes strange noises and still you are not able to figure out why, make sure that you call professionals to check the issue and get it resolved. Contact White’s Plumbing Today to have your toilet looked at and we will have it fixed in no time at all! 

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