Toilet Bowl Water Level Drops: Causes and Solutions

If your toilet bowl water level drops frequently, then there might be damage to your toilet. It’s common problem that is easy to fix, provided that you find out the root cause of the problem. It may be your toilet’s flapper, the toilet vent, or even a cracked bowl. Read on to learn why your toilet bowl water level drops, the potential causes, and how to fix them.

Potential Causes of Toilet Bowl Water Level Drops & How to Fix Them

Here are the most common causes of toilet bowl water level drops and how to fix them:

1. Clogged Vent

If debris accumulates in the toilet vent stack, the water will not drain properly, and you will hear loud gurgling noises from the toilet. It could cause other issues — like a clogged drain or a foul smell from your sewer. You can avoid this problem by simply cleaning your toilet bowl.

How to Fix It

Step 1: You need to climb up on the roof

If you don’t have a ladder, you’ll need to climb up to the top of the roof to get to the vent. It’s not easy to climb up into the attic to try and unclog a vent. Be careful and stay in a safe place. You should always use a strong rope to secure yourself when things go wrong. If you can’t work from an elevated position, you should call a plumber — they will have much more experience cleaning up air vents safely.

Step 2: Unclog the Vent by Removing Clogged Compost

Vents in our houses become dirty when exterior things get stuck in them. Birds bring in all kinds of things to make a nest, and nearby trees can block the air vent completely. If you’ve got a blocked air vent in your bathroom, you will need to use a wire to try and break through the obstructions by pushing down the vent.

Try twisting a length of wire from a long coat hanger and twisting it gently until it looks straight and long. It’s easy to unclog a blocked air vent simply by pushing a long piece of wire down the drain. Bend the wires at the ends to make a hook. It makes it more efficient if you bend the wire at the end, particularly when you want to pull clogs out of your bathroom vent.

Step 3: Pour Water down your Vent

Now try pouring water down the vent. Just attach a hose pipe to flush the drain, and the water should break down the clogs and flow freely. Remember not to use excessive pressure when you are doing this step. If the clog remains unblocked, the water will flow upwards through the pipe and cause a backflow due to the developed pressure. It isn’t something you want to experience, especially when working on a roof.

Step 4: Using a Pipe Cleaner to Clear the Clogged Vents

If water doesn’t work, you can utilize a long pipe cleaner or a toilet auger to dislodge the clogs. You can run this pipe cleaner through any air vent easily — it can go around any pipe and even penetrate curved pipes.

With a long pipe cleaner, you can easily remove stubborn clogs and clean the pipes along the way. If you push a pipe cleaner down an air vent slowly, the water will soak into the obstruction, and you will need to remove it to clean it.

Step 5: Pour Some Water Down the Vent to Test if the Clog Is Gone

Run a pipe cleaner down the vent again to test whether it is clean or not. If the water you pour down the vent doesn’t cause a backsplash, it’s a sign of a cleared air vent.

Please Note:  During winter, snow and ice can cause your vents to become blocked. You can fix this by installing a pipe insulation system around your vent stack.

2. The Placement Pipe Could Be the Problem

Water levels in toilets can be affected by the pipe placement. If a drain pipe is placed too close to the toilet, water could leak. It should be placed further away from the toilet to prevent water from leaking into the tank. If the drain pipe is set directly toward the toilet, it can affect the water level in the tank. More so, if a pipe breaks or an opening occurs in the pipe, the water level may rise or fall. If you notice that your toilet is losing water, call a plumber. You can sometimes temporarily fix leaky pipes, but you must be very careful and act quickly to prevent further damage to your home.

3. Damaged or Loose Seals

It could be that the seal between your toilet’s base and the toilet’s flange is broken. If you move your toilet a lot, you can cause the water-tight seal that seals the toilet bowl to pop open. Check around the base of your toilet to see if there is water leakage to your bathroom floor. If you see any leak, the problem may be with the ring at the bottom of the toilet. If this is the problem, you need to remove the toilet unit from the flange and install a new ring on the bottom of the toilet.

4. Issues with the Flapper Valve

If you have a perfectly functioning flapper valve, your toilet will automatically stop refilling when it is full, and you can adjust the water level. If the water level drops precipitously when you flush the toilet, it could be that the flapper valve on your toilet is leaking water. Adding a small amount of food coloring to the toilet tank is the easiest way to see if you are losing water because the flapper is failing. If it fails, turn off the water and then try to fill the toilet with water. If you see the water from the tank colored, you’ve got a defective flapper valve. You must have a new one installed.

Installing a New Flapper Valve

If the flapper valve is leaking, turn off the water supply on the pipe that leads to your toilet tank. Water will halt flowing from the supply line to the tank. Flush your toilet and remove its flapper valve. It is found inside the toilet cistern at the bottom. It may take a while to fix a leaking flapper valve, but you should be able to replace the one holding the toilet lid in place with a new flapper valve.

5. Your Toilet Water Level Is Not Correctly Adjusted

If your toilet continues losing water, it may be time to set the correct water level. Every toilet is constructed to hold different amounts of water, so it is important to know how to adjust the water level in your toilet. If you set the water level too high or too low, the toilet won’t flush properly. Adjust the Water Level by adjusting the water intake valve.

There are two positions where screwdrivers can be used: on the top and bottom of the intake pipe and at the bottom of the water tank. You will find a screw that adjusts the level of the water coming in from the tank by turning a knob that is located on the bottom or top of the intake pipe. Turning this valve to either decrease or increase the water level is possible.

6. A cracked toilet bowl

A cracked or worn-out toilet bowl may cause the water level to drop when you flush the toilet. It’s not very common for water in your toilet bowl to drop, but it sometimes happens. Inspect your bowl and the bottom of the toilet to check if it is cracked. If you can see water on the bottom of the toilet bowl or if there are water spots on the walls or floors, this may be the cause of your problem. If changing the ring on the toilet does not solve the problem, then the toilet is cracked. You’ll need a new bowl.

How to Identify the Cause of Toilet Bowl Water Level Drop

Cracks in the toilet bowl are very difficult to see, and if there is a small crack, it is usually very hard to find. And to get a full view of the interior of your vent, you would have to climb up on the roof.

So how can you find out the source of the problem? Follow the steps below to find out what is causing the water level in your bowl to drop:

  1. Run all your faucets. If there is a small crack in the toilet, it is likely the vent. Make sure that the toilet is full. Then run the tub and sink faucet.
  2. Listen for gurgling sounds. If that happens, then the vent is probably leaking. If your drain pipe is leaking water from your toilet, you should hear a little gurgling as the air being pushed through the hole in the vent causes it to gurgle.
  3. Turn off all water taps, and avoid using water while you perform this test completely.
  4. If you see the water leaking, start filling the toilet tank with water. Wait about an hour. When you fill your toilet with water, mark the water level to note where the leaks occur.
  5. Take a while and check if there is a small crack in the wall of your toilet. If it is, you are looking at a small leak. Wait for one hour to see how low it gets.
  6. Look at the level of your water in the toilet tank. If it’s low, it could be that the vent is defective. If your toilet is constantly running water down your drain, there is likely a small crack in the bowl, allowing water to leak from it.


What is the Right Level for the Water in a Toilet?

If the water in your toilet tank is not rising, look for a mark on the top of the tank that indicates the appropriate level of water. If the level is too low, you may have a clogged float or a faulty toilet. However, if the toilet doesn’t mark the correct level, you should ensure that the toilet water level is about 1 inch below the overflow pipe.

What Measures the Water Level in a Toilet?

Generally, the water level of a toilet is determined by the height of the P-trap. But, some issues can interrupt the process of determining the water level. When pipes become clogged, the water in your toilet bowl could be extremely low. And as covered in this article, there are several reasons why the water level in your toilet may be too low. You could have problems with the pipe placement, a spoiled fill valve, a cracked toilet bowl, or a clogged sewer vent.

Why Is the Toilet Dry?

If your toilet bowl is always empty, it could be that the toilet does not receive water from the tank. You may also have some other problems. The water supply to your toilet may be interrupted or completely cut off. Check the water shutoff valve that’s located behind your toilet. Make sure that it’s turned on.

It could also be a blocked intake valve. If it is clogged, it will need to be replaced. It could also be that the toilet float keeps getting stuck in place. Try moving it gently until it stops sticking! Moving the float in the toilet bowl while gently moving the float in the tank should fix the problem.

Wrapping Up

Hopefully, our suggestions will help you fix low water levels in your toilet bowl! If you follow our instructions and the problem still persists, consider hiring a professional plumber. Remember that low water levels in your toilet bowl will affect the flush efficiency, resulting in continuous clogs and other issues.

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