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Slow Flushing Toilet

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Toilets are designed to serve one purpose and one purpose only: get rid of waste swiftly and efficiently. In most cases, these fixtures have no problem getting the job done. With a simple push of a button or lever , the contents of the bowl are sent down the drainage pipe in seconds.

So, what are you supposed to do if the process takes longer than a couple of seconds?

That dreaded slow flush is much more than just a minor inconvenience. Toilets rely on the force of gravity and sudden pressure to get rid of waste. When something is preventing your toilet from flushing normally, you need to address the problem to ensure that worse problems don’t occur in the future.

Here are some common causes for a slow flushing toilet and some things you can do to fix it.

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Not Enough Water

Sometimes, the culprit is a lack of flushing water! As we mentioned earlier, toilets need a sudden surge of water to drive waste down.

Let me explain…

At the bottom of the toilet bowl is a trap. On unskirted toilets, you can see the curve of the trap. It acts as a barrier between the drainage pipe at the bowl. Not only does it prevent gases and waste from creeping back up into the bowl, but it also plays an important role in the flushing process.

You see, that trap creates an air seal. The upper curve of the trap is all air and the water level from the bowl doesn’t go all the way around. That is, however, until you flush. Flushing fills the trap to create a siphon. The whole flushing process is triggered by extra water from the toilet tank that pushes the water level past the siphon point. This causes the forces of gravity to kick in and do the rest of the job.

If you don’t fill the bowl enough, water isn’t able to get past that trap curve to initiate the siphon.

Remove the lid of your toilet tank and take a peek inside. You’ll see a lot of complex components. The most important thing you want to pay attention to is the water level. If it’s not up to the fill line, you may need to make some adjustments.

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The Fix

Ideally, the water levels in your toilet tank should be about half an inch below the overflow pipe. If it doesn’t get that high, you need to adjust the toilet fill valve.

This valve’s purpose is to trigger the filling mechanism. After you flush, the tank will fill with water until the fill valve tells it to stop. Typically, the valve can be identified by the large air-filled rubber ball or floating cup. It’s attached to the water shutoff valve.

The goal is to increase the amount of water needed to trigger the shutoff valve. To do this, just extend the floating ball farther away or raise the cup. Usually, this can be done by adjusting some screws.

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Stubborn Clogs

You may have a slow flushing toilet because of a clog. Clogs prevent water from moving past the trap. Toilet clogs are pretty common and can be caused by several different things. While you can usually see a clog or easily identify the issue, that’s not always the case.

Clogs can occur deep within the trap system, making them difficult to spot. To make matters worse, the trap might not be clogged all the way. Thus, water can still creep by. But the path water has to take may not be big enough to trigger a full flush.

You can test this out by pouring about a gallon of water into the toilet bowl. Does the water in the bowl rise quickly? If so, you’re dealing with a clog.

The quick fill means that something is preventing water from getting past the top curve of the trap.

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The Solution

The only way you can fix your slow flushing toilet is to get rid of the clog. There are many ways to do this. You can choose natural remedies like baking soda and vinegar to do the trick. Or, you can use your plunger or a drain snake to get the job done. Once the clog is removed, your toilet should flush normally again.

Mineral Deposits

If you’re not dealing with a clog or low water levels in the toilet tank, it may be an issue with the holes around the rim. Whenever you flush, water is sent gushing down into channels around the rim. Holes are strategically drilled into the porcelain to let water flow around the bowl. This creates centrifugal force that washes the bowl clean.

When those tiny holed get clogged up, water can’t get into the bowl to initiate a flush.

Usually, these holes can’t be seen. They’re well-hidden under the rim and require some special tools to clean. Even still, they get affected by hard water pretty frequently.

Hard water stains, limescale buildup, and tough mineral deposits are all caused by dissolved minerals in the water. When water evaporates, those minerals are left behind to create stains and clog up toilet jet holes!

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The Fix

The best way to take care of this problem is some good old-fashion elbow grease. You need to clean the jet holes and get rid of those deposits!

We recommend using a soft bristle brush, baking soda, and vinegar. Don’t get too harsh with the brush. You don’t want to scratch the surface of the porcelain and cause even more hard water stains. If that doesn’t work, consider using a limescale solution. These products contain glycolic acid or muriatic acid to dissolve mineral stains in minutes.


Those are the main reasons why most people have to deal with slow flushing toilets. Before you rush out and call a plumber, give our at-home remedies a shot.

The good news is that most issues can be taken care of with a few simple tools. Once you figure out what’s preventing your toilet from flushing normally, half the battle is already won! After you have taken care of the issue at hand, your toilet should be as good as new.

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