How to Adjust the Water Level In the Toilet Bowl?

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You probably aren’t a licensed plumber, but you can surely see the difference between the average and the unusual water level in your toilet. 

The water level in your toilet bowl can be higher or lower than normal, but each option indicates a problem with your toilet. So how do you adjust the water level in the toilet bowl?

Start by identifying the issue as it can be anything from a broken fill valve to clogs in the outlet drain. After determining the cause, you can get to work and fix the problem. We will show you how to do that.

How to Adjust the Water Level In the Toilet Bowl?

Many things can cause a low water level in your toilet bowl, so we need to discuss each problem separately. Here are six ways to adjust the water level in your bowl.

Solution 1: Unclog Your Toilet

A clogged toilet is one of the main bathroom incidents, so let’s talk about that first. If this happens to your toilet, the water level in the bowl will be much higher than usual because it can’t go out through the drain.

The key task is to prevent the toilet from overflowing — toilet water rises too high when flushing, so don’t do it again before unclogging. Here’s how to unclog your toilet:

Step 1: Close the Water Supply

You don’t want a single droplet to enter the toilet bowl, so remember to close the water supply before taking new steps. The shut-off valve is right next to the toilet or behind it — use your fingers to turn the knob clockwise, and you’ll close it.

However, the shut-off valve sometimes won’t shut off because it’s too stiff and rusty. In this case, you should use WD-40 to spray the valve and loosen it. After that, grab an adjustable wrench and screw the knob until you seal it.

Step 2: Empty the Toilet Tank

Now you should empty the tank — it’s not mandatory, but it can prevent ugly leakages and fill the bowl already half full. Obviously, flushing the toilet is not an option here. You can use a wet vacuum cleaner to suck the water out of the tank.

That way, you are sure that the water won’t flow out and cause an overflow in your toilet.

Step 3: Use a Toilet Auger to Break Clogs

The third step is to use a toilet auger to break clogs in the plumbing lines. An auger is a useful tool because it breaks waste balls with its sharp tip and edges. It works like this:

  • Put the auger in the bowl and push it as deep as possible
  • When it stops, rotate the handle to help the drill go further down the pipe
  • It will stop again when it reaches the clog, so it’s time to give it the extra push
  • The toilet snake will break the clog, and you’ll see the water exiting the bowl
  • Now you can pull out the auger
  • Clean the tool when you finish the work

Step 4: Open the Supply Line

Your toilet is already good, but you still need to open the water supply line. Turn the shut-off valve counterclockwise — it will let the water flow through the supply hose and into the toilet tank.

Once full, you can test-flush the toilet and watch the toilet’s water level return to normal.

Solution 2: Adjust the Tank Float

The water in your bowl can be either too high or too low if the tank float is not in the right position. But don’t worry — adjusting the ball-and-arm float is the easiest trick you’ll find in this article! It doesn’t even require the universal toilet repair kit.

Step 1: Open the Toilet Tank Lid

The float ball is a key part of toilet tank mechanisms, so the first task is to remove the tank top. It’s a plastic cover that you can lift with your fingers. In case it’s stuck, grab a flathead screwdriver to push the lid off the tank — it snaps off easily. 

Step 2: Identify the Tank Float

Now you can see the inside of the tank, which means you can see the tank float, too. Missing it is impossible — you’re looking for a big plastic ball with a metal arm right above the overflow tube.

The purpose of the floating ballcock is to regulate the water level in the tank. The higher it goes, the higher the water level — the same logic applies in the opposite direction. In other words, you can do two things:

  • Lower the float to reduce water intake
  • Lift the float to increase water intake

Step 3: Lift or Lower the Float

The ballcock has a small screw holding it tight to the fill valve. You can slowly unscrew the bolt to adjust the toilet tank’s float height. When you reach the targeted position, tighten the screw to secure the float.

Step 4: Test the Toilet

Finally, you can set the tank lid and test the toilet. Flush it to see if the water in the bowl goes back to the usual level. After adjusting the ballcock, it should reach its average.

Solution 3: Adjust the Cylinder Float

Newer toilets often come with a cylinder float instead of the standard tank float, but it serves the same purpose. Adjusting this float isn’t time-consuming.

Step 1: Close the Water Supply

Once again, start by closing the toilet’s water supply valve. Turn the knob clockwise, and you’ll seal the main supply pipe. That way, you will stop fresh water from entering the tank from the supply hose.

Step 2: Empty the Tank

Step two is to empty the tank — it’s important if you want to keep your hands dry and clean. Now that the water supply is off, you can flush the toilet to drain the tank water.

You don’t need to clean the remaining droplets because your hands won’t go that deep into the tank. The float is easy to reach, so you can move on to the next step.

Step 3: Find the Cylinder Float

How does the float look? It’s a round-shaped plastic part hanging on the rod between the fill valve and the overflow tube. Alternatively, you’ll notice the cylinder float on the fill valve directly — it surrounds the valve’s long slender tube.

It’s impossible to miss the cylinder as it’s the only round-shaped plastic element in the toilet tank. Now you know how to find it, so let’s see what to do with it.

Step 4: Adjust It

Adjusting the floating cup is simple because you only need to lift it or lower it. The former will increase the water level, while the latter will reduce the water level in the tank. That also impacts the water level in the toilet bowl.

Most times, you can drag the cylinder up or down the fill valve. However, some cylinders have a small plastic button on the side — press the button, and you can move the cylinder along the rod.

Step 5: Close the Tank and Open the Water Supply

You’ve already adjusted the float, so the only thing left is to cover the tank with its lid. The toilet is back in its place now, but don’t forget to open the water supply — turn the valve counterclockwise until it goes a full circle.

You can flush the toilet one or two times to inspect the water condition in your toilet bowl.

Solution 4: Change the Fill Valve

A broken fill valve disables the toilet because it doesn’t allow the water to flow into the tank. The solution is to replace the valve, so let’s learn how to do that.

Step 1: Close the Water Supply

You probably notice that many DIY bathroom projects start the same. That’s also the case with the fill valve replacement because you’ll have to remove the old part from the toilet tank. You know the drill:

  • Find the external water valve
  • Spray it with WD-40 to loosen the knob
  • Turn its knob clockwise

Step 2: Empty the Tank

The second step is also the same — drain the water from the tank to access the fill valve. You’ll need to clean everything because the valve stretches to the bottom of the tank. Let’s go through this process again:

  • Flush the toilet to empty the tank
  • Remove the tank top
  • Use a sponge or paper towels to dry the tank’s bottom

Step 3: Remove the Old Fill Valve

The fill valve is the tallest part in the tank, so you can’t miss it. It goes from the top to the bottom, where it connects to the water supply hose. Almost every tank hides the fill valve on the left side.

When you identify the fill valve, you can remove it by lifting it. It’s a lightweight plastic tube, so it takes minimum effort to detach it from the tank.

Step 4: Install a New Fill Valve

Once the old valve is gone, you can install a new model. Put the new fill valve in the tank and let it slide in its original position. You’ll probably hear it snap, which is a sign that the valve is in the right place.

Step 5: Reassemble the Tank

Finally, you can reassemble the toilet tank by bringing back the plastic cover. Put it on the tank and open the water supply – you’ll hear the water flowing into the tank right away.

Solution 5: Unclog the Air Vent

The air vent is a long pipe that controls the airflow in the plumbing system. It balances the pressure in the waste drain, allowing clean water in the toilet bowl after flushing.

If the air vent is clogged, the bowl is losing water. Here’s how to fix it:

Step 1: Climb the Roof

The problem with air vents is that you must approach them through the roof. That’s how they get clogged — falling leaves and bird nests block the air supply pipe. Make sure to secure the perimeter, so you can work safely.

Step 2: Use a Garden Hose to Clean the Vent

You need to clear the vent from waste blockages. Place a garden hose into the vent pipe and turn on the water supply at full power — it should clean out all debris from the ventilation tube.

If the clog is too hard, the water may flow back and splash you. Keep that in mind to avoid unpleasant surprises. 

Step 3: Use an Auger to Break Clogs

In case you’re unable to dissolve the clog with water, use a toilet auger. It’s a long and sharp wire that breaks waste blocks with ease — you only need to insert it into the tube and push.

When the drill breaks the clog, you’ll feel it going down the drain effortlessly. That’s how you know when to take the auger out of the air vent.

Step 4: Pour Water in the Vent

The air vent has no clogs anymore, but you should still clean it with water to eliminate waste remnants. That way, there won’t be folds and deposits to start forming new waste blocks. It’s a practical trick that prevents future clogging.

Step 5: Test the Toilet

The last task is to test the toilet by flushing it.

Now that the air vent is clean, the pressure should be strong enough to push the water in the toilet bowl. The water level will stabilize, but you can activate the flush system a few times just to make sure everything’s good.

Solution 6: Replace the Toilet Bowl

If you notice that the toilet is leaking at its base, you are probably dealing with a cracked toilet bowl. In such circumstances, the solution is to replace the toilet bowl.

Step 1: Close the Shut-off Valve and Empty the Tank

Once again, we start by shutting off the external water valve. You know how it works – grab the knob and turn it clockwise. After that, you can empty the tank by flushing it. Use a sponge or dry towels to remove the last droplets from the tank.

Step 2: Detach the Supply Hose and the Tank

The second step is to detach the supply hose, a metal pipe leading the water from the shut-off valve to the tank. It has a threaded nut – unscrew it counterclockwise to remove the hosepipe.

After that, you can also remove the tank – it has a pair of tank bolts that you need to unscrew with a flathead screwdriver. The empty tank is not heavy, so it’s easy to lift it and place it on the bathroom floor.

Step 3: Remove the Old Bowl

The next task is to remove the old toilet bowl because its water level keeps dropping

This part also has a pair of bolts keeping it firmly against the bathroom flooring, so you’ll have to unscrew them as well. It shouldn’t be difficult, but use WD-40 if you can’t twist the screws.

After removing the bolts, you can grab the bowl and detach it from the floor. The bowl is not too heavy, but be careful when lifting it – you don’t want to hurt your back in the process.

Step 4: Install a New Toilet Bowl

Step number four is all about installing a new bowl. Place the item in its position — you’ll see the outlet drain with the toilet flange. The bowl should cover the flange when you place it on the bathroom flooring.

Once it’s there, you must support the new model with a couple of bolts. Turn them clockwise this time as it will keep the bowl strongly against the ground. Try to push it with your hand – if it doesn’t move, the bowl is properly set.

Step 5: Reinstall the Tank and Open the Shut-off Valve

The last task is to reinstall the tank and open the shut-off valve. This is the process:

  • Put back the tank and tighten it with bolts
  • Attach the metal hose to the bottom of the tank
  • Twist the shut-off valve counterclockwise to open it
  • Let the water fill the tank, and then flush it

When you do all that, you should check the toilet bowl water level. Without cracks, the new bowl should keep the required level of water around the clock.

The Bottom Line

When you notice the unusual water level in the bowl, rest assured something is wrong with your toilet. It can be one of these things:

  • Cracks on the toilet bowl
  • Clogs in the outlet drain
  • Faulty position of the tank float
  • Faulty position of the cylinder float
  • Blocked air vent
  • Broken fill valve

All problems demand a different approach, but we showed you a step-by-step guide on dealing with each one. The job is easier than it seems – just follow our tips, and you won’t have to call a plumber!


How can I adjust the water level in my toilet tank?

You can change the water level in your toilet tank by repositioning the ball-and-arm float or the cylinder float.

Both parts determine the water level — pushing them down will lower the amount of water your toilet gets. If you lift them, the water level in your toilet tank will go up as well.

Why is the water level in the toilet bowl so low?

The water level in your toilet bowl can be low for many reasons. The most common include a cracked toilet bowl or a blocked air vent. You could also struggle with clogs in the outlet drain or a damaged fill valve.

The last two alternatives are the tank float and the cylinder float — if their position is not right, the water level in your bowl will be either too high or too low.

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