My Account
With just a little knowledge of what’s going on in your toilet tank, you can troubleshoot a variety of issues related to this all-important fixture in your home or rental property. In this tutorial, I’ll be talking specifically about how to adjust the water level in a toilet.
How to Adjust the Water Level in a Toilet: Step-by-Step Guide
In this step-by-step guide, I’ll show you two things to quickly check to make sure your toilet is operating as it should. Then, I’ll walk you through two different adjustments you can make that will bring the water line in the toilet bowl to the desired level.
Rather watch than read? Check out this 8-minute video.
DISCLAIMER: This video and description contain affiliate links, which means that if you click on one of the product links, I’ll receive a small commission.
How to Adjust the Water Level in a Toilet: Supplies and Tools
No supplies or tools needed, except maybe a screwdriver.
Understanding the Parts in Your Toilet Bowl
Before we get into adjusting the water level in your toilet bowl, let’s first review the components in the tank. Then we’ll go over what happens when you flush the toilet.
The components in a toilet tank are:
- the fill valve
- the fill tube
- the overflow tube
- the float and lever arm
- the handle
- the flapper
The components in your tank might look a bit different but essentially these are the working parts of any toilet.
Understanding What Happens When You Flush the Toilet
When you flush the toilet, the handle releases the flapper, which allows the water in the tank to drain out into the bowl and flush out its contents.
When you release the handle, the flapper closes, sealing off the tank so that it can start filling up again. Water comes into the tank from the base of the fill valve. Water is also going through the fill tube into the overflow tube to refill the toilet bowl.
As the water level in the tank rises, the float will rise with it until it pushes the lever arm above it to a point where it closes a little diaphragm inside the fill valve and shuts off the flow of water. This stops water from flowing into both the tank and the bowl.
So now you see how the water level in the toilet tank is connected to the water in the toilet bowl. Basically, the water level in the tank regulates the water level in the bowl.
Note that for a toilet to flush properly, the float must move freely so that it can ascend and descend with the water level.
Low Water Level in a Toilet Bowl: Two Things to Check
First Thing to Check: Complete Emptying of the Tank
When you have a low water level in your toilet bowl, the first thing to check is that the tank is emptying completely.
To illustrate this, I’ll press the handle quickly and then release it. In this case, the tank did not fully drain, which means the flow of water will be limited. As we previously discussed, this will also impact the amount of water in the toilet bowl.
Second Thing to Check: The Fill Tube
The second thing to check when the water level in your toilet is low is the fill tube.
If the tube is leaking, this will result in less water going into the toilet bowl.
If the tube is positioned incorrectly inside the overflow tube, this can also create a problem. A fill tube sitting below the water line can create a siphon effect that negatively impacts the functioning of your toilet.
The fill tube on this toilet has a clip that holds it in position above the water line and keeps it centered over the opening of the overflow tube.
In older toilets, you might have a fill tube that just dangles into the overflow tube. You’ll want to adjust it so that it doesn’t sit below the water line.
How to Adjust the Water Level in a Toilet
To adjust the water level in a toilet bowl, there are two things you can do. Note that these adjustments can be used to increase or decrease the amount of water in your toilet bowl.
The most common way to change the water level in a toilet is to adjust the lever arm on the fill valve assembly. You should be able to do this by hand. If not, all you need is a screwdriver.
Turn the round head of the lever arm in a clockwise direction to raise the water level. (If you’re interested in saving a little water with each flush, turn it in a counterclockwise direction and you’ll lower the water level.)
Hold the arm steady as you do this. When you release the arm, more water should start coming into the tank if you’ve adjusted it to increase the water volume. (If you’ve adjusted the lever arm to decrease the water level, you’ll need to flush the toilet to see the effects of the adjustment.)
The second way to increase the volume of water in a toilet is to elongate the tubular body of the fill valve. This is a matter of turning the ring to unlock it, pulling on the center section to extend it to the desired height, and turning the ring to relock it.
Here’s another view of the interior of the toilet tank.
From this perspective, you can see the water line indicated on the overflow tube. When the water in the tank is at this level, you’re meeting the specified design target for gallons (or liters) of water per flush for that toilet model.
How to Adjust the Water Level in a Toilet: Conclusion
Voilà! Now you know how easy it is to fix the issue of a low water level in your toilet with some basic knowledge and a couple of simple adjustments that don’t even require any tools.
If your objective is to reduce your water consumption, you can use these same adjustments to easily decrease the amount of water your toilet uses.
Other Toilet-Related Repairs
For other useful toilet-related articles, please have a look at our step-by-step guides on how to fix a broken toilet handle and how to flush a toilet when your water supply gets shut off.
To Leave Comments and Questions
Now you have the knowledge and confidence to adjust the water level in a toilet all by yourself!
If something doesn’t make sense or if your situation is a little different, please leave a comment under the YouTube video. I check the comments on a daily basis and am happy to help out.
Don’t forget to subscribe to our channel as we have weekly videos coming out to help you with your everyday home repairs.
We’ll catch you on the next one! Take care.
