How to Adjust Water Level in the Toilet Bowl

Some of the common toilet issues you may encounter are high or low water levels in the bowl. And because the water level in the bowl, in most cases, directly relates to the float in the tank, the solution would then be to adjust the water level in the tank.

To adjust the water level in the toilet bowl, first is to adjust the ball and arm float to its right height. This ensures sufficient water gets into the tank, consequently leading to a full flush. If that doesn’t seem to work, you may need to replace the fill valve entirely. You can also check for any cracks on the bowl and blockages in your home plumping vents.

It is important to note toilets operate differently based on how the brand manufacturers intended them to work, hence the adjustment instructions can be different. The following is an in-depth look into how you can adjust the water level for common toilets, plus two specialized sections for the Kohler toilet and fluidmaster.

General Steps to Adjust Water Level

Before we begin, it’s essential to note that the correct water mark in the toilet bowl should be at the end of the internal p-trap.

Low water level in toilet bowl
Low water

If it’s higher or lower the line, then you need to fix the underlying issue and adjust the water level in the tank. As for this article, we shall solely look at how you can adjust the water level.

Adjust the Ball and Arm Float

The right level for the water should be one inch below the overflow tube. If it’s not there, you need to adjust the float accordingly.

  1. Remove the tank lid by lifting and setting it aside on a stable surface.
  2. Check the water level in the tank to make sure it’s within the industry standard. That’s one to two inches (2.5 to 5cm) below the fill valve. You can also check against the overflow tube. If the measurement is off, move to the next step.
  3. Turn off the water supply either from the main shutoff valve or the one inside the house. Just locate it and rotate the known clockwise to seal.
  4. Drain the water from the tank to the bowl by flushing. There shouldn’t be more water in the tank. Begin to fix the float.
  5. Check for damages its defects on the float. If it’s damaged, it could be best to let a professional handle the work from there.
  6. If not, proceed to check the height of the float (plastic ball) attached to the arm. Align it to the right height to ensure once it refills it will be at the right height.
  7. You can use a screwdriver to adjust the height lower or higher. The screw is located directly on top of the fill valve. Turn it clockwise to raise the level and counterclockwise to lower the level.
  8. Now open the valve to allow water in. Observe the water level in the tank. Once full, flush and look at the water level in the bowl. If not satisfied, call a plumber.

Note, if you can’t measure the distance on the water level, look at the line that should be etched on the porcelain tank. That should show you the water level.

Replace with a New Fill Valve

If the ball and arm float is working well, then you may need to replace the fill valve with a new one.

  1. For a fill valve replacement, there should be completely no water in the tank. So locate your water supply valve to the toilet and shut it off by rotating clockwise.
  2. Now detach the fill valve from outside the tank. There will be two nuts or screws that are connected to the water supply line. Just pull out that line to expose the valve, then unscrew it. It should be easy to open the nut, if not use a pair of pliers or an adjustable wrench.
  3. Pull the old valve out of the tank along with the float. Discard the old and put in the new one.
  4. Fit the bottom part of the valve through the hole at the base of the tank. Secure it tightly to ensure there are no leaks.
  5. Now assemble the remaining parts of the toilet and attach the water supply hose from the bottom of the valve.
  6. Screw in the larger nut. Ensure it’s snug enough to avoid leaks.
  7. Turn back the water supply and allow the tank to fill. Check if it’s at the right water level, flush, and confirm that it’s fixed.

Inspect for Bowl Leakages

The above methods revolve around the toilet tank but there are cases when the tank is okay but you still notice that water level in the bowl is either too low or high.

This could be a sigh that your bowl is cracked allowing water to get out or leak from the cracks. This eventually leads to a low water level. Fix this issue as soon as possible to ensure the levels are right. If you cannot do it on own look a professional plumber.

Toilet bowl free of cracks
Toilet bowl

Unblock the Plumbing Vents

Another not-tank-related problem causing unusual water level in the bowl is blocked plumbing vents in your home.

The vents should be clear to allow air in. Without the air, the pressure within the vents will not be balanced. If the vents are completely blocked, air will not get in. All these means poor flow of water in your home’s plumbing system.

How do you know that the vents are blocked? If your toilet gurgles and splutters when you empty the bathtub or flush a different toilet in another room in your house.

To clear the vents, find a ladder, get onto your roof and try flushing your pipes out with water from a garden hose. To avoid future blockages simply to find a way to cover the vents to avoid dirt and debris from getting in.

If the issue is not yet fixed, do look for a plumber to have a look at what else could be wrong with the toilet.

How to Adjust Water Level in the Toilet Bowl – Kohler

The Kohler brand is a leading toilet manufacturer in the USA. They have unique toilets fitted with different parts working differently than the other brands. Newer Kohler toilets have one piece floats rather than the traditional ball and arm float, hence, you may need to fix them a little different from the first illustration.

  1. In the toilet system, you should see a cylindrical float attached to the rod of the fill valve. They’re very easy to assemble and disassemble so it should be a problem to do it yourself.
  2. To begin, remove the lid to the tank and check the water level. If it’s either high or low, you will have to follow the steps to adjust for a good water level.
  3. Shut off the supply to the tank and flush the tank to allow you to work much better. You should have a rug in case of water spills to the floor.
  4. Locate an adjustment stem that’s normally on the side of the cylindrical float. The adjustment stem is the overflow tube which is just a tall tube in the middle of the tank. It will also be attached to the large fill valve.
  5. If you don’t see the valve, check the sides.
  6. Using the adjustment stem, increase or decrease the water amount getting into the tank.
  7. There’s a release clip next to the float that can be used to adjust the water level. Simply raise the clip by half an inch to raise the after level and lower the clip for opposite results.
  8. Open the supply valve and let water into the tank. Check to see the level. If you’re not happy with the result, flush the water and adjust until you get your desired results.

Some toilets have an adjustment dial, just raise or lower it by a centimeter or 1.25 cm. You can use your fingers to hold the dial on the end of the adjustment stem and twist it clockwise or counterclockwise.

Clockwise will lower the height and counterclockwise will raise the height. When you get a suitable height, turn on the water supply and flush. Some adjustment stems, are tightly secured so you can use a wrench to loosen them up a bit.

How to Adjust Water Level in The Toilet Bowl with Fluidmaster

The Fluidmaster fill valve is said to be faster than other models. In fact, they claim that it’s the quietest and most powerful replacement for the Kohler toilet.

It offers two times the speed of bowl refill and 1.6 of lower GPF toilets. Furthermore, it has a 400AH which is known for being a very powerful fill valve.

This Fluidmaster valve is guaranteed to prevent inadequate and excessive refill of water on the backs, which is why it’s the best replacement if you’re trying to adjust your water level in the bowl.

To install it;

  1. Remove the lid to the tank and mark where you want to adjust the water level to.
  2. Close the water supply, flush the toilet, and completely dry the tank with a sponge.
  3. Detach the connector and the fill valve, then remove the old valve.
  4. Replace with the fluidmaster valve. As you place it in, keep the shank washer with the flat side facing upwards.
  5. Set the upper section of the fill valve three inches above the overflow tube. On top of the shank, you should see a critical sign that shows where the water level is.
  6. Check the stem if you want to add more water to the tank. Remember clockwise to lower and counterclockwise to increase the level.
  7. Now for the lower part of the valve, press it down and tighten its lock nut from the outside of the tank. Don’t overtighten.
  8. Connect the refill tube to the clip and attach it to the right side of the overflow tube. The other side should be at the fill valve.
  9. Connect water supply, allow to fill with water, then adjust the water level.

The right water level allows for an effectively working toilet as when the water level is low, there won’t be enough water to fill the toilet bowl after flushing.

This means that the toilet can’t be cleaned and the waste won’t be washed away. If the water level is high in the bowl, then there’s a clog in the pipe that needs to be fixed sooner rather than later or you can’t use the toilet in case you flush and the water overflows.

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