Easy Steps on How To Adjust the Water Level in Your Toilet Bowl and the Causes

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How to adjust water level in toilet bowl and maintaining the correct water level in your toilet bowl is an essential part of keeping it functioning properly. An excess of water will cause the toilet to overflow while not having enough water will result in a weak flush that can potentially lead to blockages.

In this blog post, we will show you how to adjust the water level by adjusting the ball and arm float and also the cylinder float. We will also cover some common causes of low or high water levels in a toilet bowl, and finally tips on how to keep the water level at the right height.

Let’s get started!

Why Would You Want To Adjust The Water Level In The Toilet Bowl

Swiss Madison Well Made Forever SM-1T254 St. Tropez One Piece Toilet, 26.6 x 15 x 31 inches, Glossy White

You may not even realize that the water level is running low or simply not think it is important enough, but the truth of the matter is that a constant level of water is required for a toilet to function correctly.

A toilet with not enough water to flush the waste away will be more susceptible to blockages, while a toilet tank with too much water could potentially not only overflow the toilet on a flush, it will cost you more in water bills in the long run.

How to Adjust Water Level in Toilet Bowl in a Single and Dual Flush Toilet

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This is a relatively easy job to do yourself without having to call out a plumber. Both the water level in the tank and the water in the toilet bowl are controlled by the float situated in the toilet tank.

There are a couple of different floating devices we will look at as well as any other parts that may be contributing to this issue.

How to Adjust a Ball-and-Arm Float

Danco 80816 Complete Toilet Repair Kit Fill Valve, Flapper, Rod, Float Replacement, White

1. Set toilet tank lid aside

Typically, these lids are constructed of ceramic and if not placed correctly can break so you will need to be careful. Take the lid and place it out of the way on the floor on top of a towel or a mat.

2. Measure the water level inside the tank –

Generally, the water sits approximately 2 inches below the open pipe in the center (known as the overflow tube) and the fill valve. Most tanks come with a mark inside the tank that indicates where the level of water should be.

Any significant difference is an indication that there is an issue somewhere in the system.

3. Turn off the water and flush

You will need access to the parts within the tank so turning off the water is essential. Most stop valves are situated under the toilet tank, simply find and turn the handle clockwise fully. Empty the tank by flushing the toilet.

4. Inspect the float and fill valve

If the float or fill valve appears to be damaged and needs to be repaired then you may need the help of a plumber.

5. Check the height of the float device

Usually, a red plastic ball floats on the water surface connected to the top of the fill valve via a metal arm. The higher it is allowed to sit the more water will fill the tank.

If the float has a hole then it will let water in and not function properly and will need replacing as this may be the cause of your high or low water level.

6. Adjust float height

Sitting on top of the fill valve is a screw that when turned clockwise will increase the amount of water in the tank or lower it if turned anti-clockwise.

Top tip – Ensure to always turn one full rotation of the screw. If the screw is stuck and not turning you can twist the float making sure again to turn one complete rotation.

7. Turn the water on and flush the toilet

Reach back and turn the water supply valve back on and let the toilet fill up again. Flush it and check the water level in the toilet bowl which should sit halfway. If it is higher or lower then you will have to repeat the steps above until it sits in the right position.

How to Adjust a Cylinder Float

1. Set toilet tank lid aside

Take the lid and place it out of the way on the floor on top of a towel or a mat so that you don’t damage it.

2. Turn off the water and flush

Turn off the water as you will need access to the parts within the tank. Most stop valves are situated under the toilet tank, simply find and turn the handle clockwise fully. Empty the tank by flushing the toilet.

3. Establish the cylinder float

Modern toilets now come with a floating cup which is essentially a one-piece cylinder-shaped floating device that is attached to the fill valve tube. This type of floating device is very easy to work with and even replace if needed.

4. Adjustment stem

The adjustment stem is how you control the amount of water there is in the tank. Typically, it is a long tube that is attached to the fill valve, extending out at a 90-degree angle or sitting parallel to the valve.

5. Release clip

A lot of cylinder floats come with a release clip that allows you to easily move the cylinder up and raise the water level and down to reduce it. Alternatively, your cylinder float will have an adjustment dial.

6. Adjust the float

Turn the dial situated on the stem base clockwise to reduce the height and anti-clockwise to increase the height. Ensure that when turning the dial, it is always a full rotation on every turn. Some models have a screw that you can turn if the dial is jammed to adjust the height of the cylinder.

7. Turn the water on and test

Turn the water on and flush the toilet and check if the water in the bowl has either gone up or down. If the bowl is not half full then you may need to tweak the dial a little until you get the correct water level.

Installing a New Fill Valve

Kohler Genuine Part Gp1138930 Silent Fill Toilet Fill Valve Kit, 12.5" L x 3.5" W x 3" H inches

If your toilet is continuously running then you may have a faulty fill valve and adjusting the floating ball or cylinder will not affect the water level. To resolve this issue you may need to replace the fill valve altogether.

1. Drain the water

The shut-off valve typically sits behind the toilet under the tank. Turn off the water supply and flush the toilet emptying the tank. Soak up the remaining water with a rag or a sponge making sure the tank is dry.

2. Remove the water supply hose

Unscrew the nut that connects the water supply hose to the fill valve and then once undone remove the supply hose. Proceed to remove the nut inside the tank that holds the fill valve in place.

3. Remove the faulty fill valve

Once the nuts have been removed take the float and fill valve out of the tank. The fill valve and float should come out with relative ease but ensure you are careful and don’t damage anything in the process.

4. Install the new fill valve

Put the new fill valve through the hole in the tank and tighten the plastic nut at the base securing the fill valve to the tank.

5. Reconnect the water supply hose

Grab the water supply hose and feed it on the fill valve and tighten the nuts ensuring all the washers are in place to prevent any leaks.

6. Turn the water on and test

Once the supply hose is securely on, turn the shut-off valve to allow water to flow into the tank. Keep an eye on the connection between the fill valve and the water supply hose to see if any water is leaking.

If you see any water leaking, tighten the nut. Flush the toilet a few times and check the water level is where it should be.

What Are Some Common Causes of Low or High Water Levels in a Toilet Bowl

If the water level in your toilet bowl is below half or there is excessive water then the following could be the cause:

Clogged toilet vent

A clogged toilet vent will lead to bubbles appearing in your toilet bowl. You will need to climb to the rooftop and just clean out the vent to allow air to flow through.

Faulty toilet valve

A faulty toilet will need to be replaced, at the very least it will need to be removed and repaired. The removal process is covered in this article.

Clogged pipes

If the level of water in your toilet bowl is fluctuating then this could be caused by a blocked pipe. Use a plunger or an auger to open the drains.

FAQS Frequently Asked Questions

What does the float do in a toilet?

The float essentially controls the amount of water that is allowed to enter the tank. The float moves up as the water fills up and eventually stops the water flow as it reaches the set height and it goes down when the toilet is flushed the water drains away opening the valve to fill up the tank again.

How to adjust the water level in an American standard toilet bowl?

The American standard toilet is similar to modern toilets in that they have a screw that can be turned to adjust the height of the water level. Just access the tank and locate the screw and turn clockwise to increase the water level and anti-clockwise to reduce the water level.

What determines the water level in a toilet bowl?

The internal P-traps outlet pipe’s height will determine the amount of water in the toilet bowl. If there is too much water in the toilet bowl then it is likely that there is a blockage in the pipe.

Why is my toilet bowl almost empty?

If the pipes are not correctly vented this can cause back siphonage sucking all the water out. If the flapper is damaged then it will cause the toilet to flush randomly.

How high should the water be in a toilet?

The toilet tank water should sit around 2.5-5 cm (1-2 inches) under the top of the overflow tube and the fill valve. Any fluctuation in this water level can cause issues.

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