How to Adjust the Water Level in Kohler Toilet Bowl? – 5 Ways

Written by

Paulk Webb


Freddie J. Hagopian

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how to adjust water level in kohler toilet bowl

An adequate water level is essential in toilets to maximize their functions. The lack of water will not allow us to flush our waste, but an excess thereof will skyrocket the bills.

That’s why we need to learn how to configure our tank’s setup, and great news: it’s pretty easy if we follow instructions.

Adjusting water levels may differ depending on the commode’s brand. In this article, we will teach you how to adjust the water level in a Kohler toilet bowl in particular, from fully opening the shut-off valve up to replacing the Canister flush valve.

Ways to Adjusting the Water Level in Kohler Toilet

1. Fully opening water shut-off valve


Probably the most basic Kohler toilet troubleshooting method in terms of water supply and level is checking if the shut-off valve is fully turned on.

If all the parts of the commode are new and working, then the reason why a Kohler toilet bowl is not filling up with water is that not enough water is entering the hose towards the fill valve, because the shut-off valve may only be half open.

2. Float valve modification


The first approach for controlling water levels is Kohler toilet fill valve adjustment. This is often called the float valve, and it’s the part that is responsible for regulating the tank’s water level.

To perform the adjustment, follow these steps:

  • Keep the shut-off valve on for continuous water supply
  • Locate the tank water level screw on top of the fill valve.
  • Turn the said screw counterclockwise if you want to raise the water level, and turn clockwise if you want to lower it.

The Kohler toilet water level is marked with a line at the back of the tank or at the flush valve, so make sure to check it while adjusting.

Too much water in the tank is equally problematic as a lack of it since the tank might overflow or might not flush successfully.

3. Toilet bowl water level adjustment


If the Kohler toilet doesn’t have enough water in the bowl, your bathroom will reek of sewage smell. This is because the standing water prevents sewer gases to flow inside your bathroom, keeping the clean aroma.

Adjusting the water level in the Kohler toilet bowl is simple but may take a few tries. To begin, follow the steps below:

1. For this method, we don’t have to turn off the water shut-off valve. Start by lifting the lever chain to slightly lift the flapper as well.

Doing this will increase the water level in the toilet bowl. Continue letting the water trickle until the water stops rising.

2. The level where the water stops rising is the seal height. Flush the toilet once and pay attention to where the water in the bowl stops.

3. If the Kohler toilet bowl’s water level is too low or below the seal height, twist the seal screw clockwise. If the water ends up too high, turn the screw counterclockwise.

The seal screw is located on the side of the fill valve. Adjust this until the standing water in the bowl reaches the seal height.

4. Fill valve replacement


How to Replace a Toilet Fill Valve | Toilet Repair | The Home Depot

What to prepare:

  • new fill valve
  • adjustable wrench

If adjusting the water level in the toilet bowl seems impossible, then maybe there’s a problem with the fill valve, not allowing the tank to fill properly.

As we have mentioned, the fill valve is responsible for regulating the tank’s water level. If there’s not enough water, we will have trouble flushing the waste and raising the water level in the toilet bowl to avoid sewer gases from reeking.

Kohler either uses a ball float or a float cup in their fill valves, so make sure to check the old one before buying a replacement.

  1. Turn off the water shut-off valve and flush the toilet to empty the tank.
  2. Unscrew the water supply hose from the toilet.
  3. By using the adjustable wrench, unscrew the mounting nut below the tank that holds the fill valve assembly.
  4. Take out the old fill valve and prepare the new one. Adjust the height and make it at least 1 inch higher than the overflow tube.
  5. Insert the shank into the tank and secure it with the mounting nut.
  6. Attach the refill tube to the overflow tube; trim it if necessary.
  7. Reattach the water supply hose to the tank and turn it on to refill.

Both the ball and cup-type floats have an adjustment screw to regulate the water level.

5. Flush valve replacement


Adjust and Install a Canister Flush Valve and Seal in Your Toilet

What to prepare:

  • new flush valve (Canister)

The flush valve is responsible for releasing water from the tank to the bowl, once we pull the lever outside. If this is not working properly, the tank may have trouble reaching the water line or the flushing mechanism might fail.

To install the new flush valve on a Kohler one-piece toilet—such as the Rialto, San Raphael, Cabernet, and Pillow Talk—we can follow the easy steps provided by Kohler itself.

  1. Turn off the water shut-off valve and flush the tank.
  2. Remove the lever chain from the old Canister or the “twist and lock” valve.
  3. Remove the refill tube from the top of the old Canister valve.
  4. Rotate the guide in the middle counterclockwise and take the Canister valve out of the tank.

Also, replace the seal at its bottom.

  1. Insert the new Canister flush valve and rotate it clockwise to lock it.
  2. Attach the refill tube to the top of the valve and connect the lever chain.

Frequently Asked Questions


Why Does the Water Level in the Kohler Toilet Bowl Seem Low?

The water level of a Kohler toilet is low for various reasons. It can be because it’s set up too low in the tank or in the bowl.

There could also be a damaged tank part—such as the fill valve or flush valve—hindering the commode from reaching adequate water levels.

Kohler toilet adjustments are easy just like with other brands, and sometimes all we have to do is adjust the float and seal screw, or fully open the water shut-off valve. You can follow the instruction above to do Kohler toilet adjusting water level in its bowl.

What Is the Ideal Water Level for the Toilet Bowl?

Toilet tanks normally have an indicator for the recommended water level. For Kohler, we can find the indication either:

  • at the back of the toilet tank or;
  • at the flush valve.

For typical measurements, the tank’s water level is 1 to 2 inches below the overflow tube and the fill valve.

For the bowl’s standing water, we just have to determine the seal height by adjusting the seal screw.


Reaching the recommended water level for both the commode’s tank and the bowl is essential to maximize its functions. To answer how to adjust the water level in a Kohler toilet bowl, we have to first fully open the shut-off valve for unrestricted water supply.

Next, we have to configure the height of the toilet float in the fill valve for the tank’s water level, and the seal screw to increase or decrease the water in the bowl. There are instances that we have to replace the parts too, such as the fill valve and the flush valve.

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