toilet tank not filling up with water

Toilet Tank Not Filling Up with Water (Solved!)

If your toilet tank not filling up with water and you are worried, do I need to replace it as you can not use it as it is not flushing? Then worry not. You can fix it at home using the steps I will share in this article.

Many things can cause this problem. But the most common toilet tank issues are listed below.

  • Water supply issue
  • Arm handle issue
  • Fill valve issue
  • Flush valve issue
  • Toilet trip handle issue
  • Boober or Float issue

Your work here is to find out what is causing then you can fix them.

How Does a Toilet Tank Work

How Does a Toilet Tank Work

Okay, before you try to fix it, you must know the basics of the toilet flushing system. So that it makes more sense when I talk about those components and how to fix them.

In a toilet tank, there are mainly two parts, one is the Fill valve that is responsible for filling the tank with water connected to your water supply line, and the other one is the Flush valve that is connected to your outside handle using a plastic arm. 

When you press the handle, the Flush valve opens up, and the water goes to your toilet to flush out the waste. And then, the Fill valve starts working to fill the tank again until it is full using a Boober or Float mechanism that is responsible for measuring how much water is available in the tank. 

That is the whole mechanism of the toilet tank. You can see this if you open up your toilet tank right now.

Also, read: Toilet tank leaks when flushed? How to fix it at home

How to Fix Toilet Tank Not Filling Up Issue

First, you have to find the issue that is causing it and then you will fix it using the steps explained here. So let’s start with the water supply line to see if there is an issue.

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1. Look for Water Supply Issues

Look for Water Supply Issues in the toilet tank

The water supply line of your toilet tank is located on the back of your toilet, close to the ground. Check if it is on. And also by turning it on and off in order to know how much water you are getting in your tank.

Here two problems can occur, and those are as follows.

  1. Broken Supply Line: If your switch or a water supply line is damaged and is malfunctioning, it can cause this problem why is your toilet tank not filling up with water? On and off it and see the difference. If nothing happens, then you may need to replace it. Just buy a new one, cut the PVC, and replace it.
  2. Clogged Water Line: If your toilet tank is old, the supply line is clogged or has dirt. This dirt is blocking the water supply. If that is the case, you will notice that the water is flowing but slowly. In that case, clean the pipe to fix this issue. If you can not, change that small pipe for a better experience.

You can use any chemical to clean the pipe or use some home detergent. If you can, then the issue will be no more. If the problem persists, the main supply line has an issue. And for that, you need a plumber who can identify the issue and solve it.

2. Malfunction of Trip Handle

Malfunction of Toilet tank trip Handler

There are many small things in the trip handle inside the tank that you can see if you open the lid up. There is an arm that is very visible to you. That arm can get bent or twisted, resulting in not opening the Flush valve properly. That is why your handler is not working properly.

  • All you have to do is twist it back using your hand back where it was. But be careful as it is made of plastic, and you do not want to break it.

Although, the arm is easy to replace and does not cost that much. Try to fix it and if that does not work, replace it.

3. The Flush Valve is Damaged

The Flush Valve of your toilet is Damaged

The flush valve is like a Cap. When you open it, the water flows through your toilet, and after that, it automatically shuts off until you press the flush handle again.

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If that Flush valve is broken somehow, the water will continue to flow to your toilet as there is a leak in the Flush valve. It happens when your tank is old, where dirt can prevent the valve from fully closing, resulting in a leak.

To fix this issue, you have to clean it off using some brush or detergent and then reinstall it back where it was. Here is how you do it.

  • Turn off the water supply.
  • Empty the tank altogether.
  • Open up the box slowly.
  • Disassemble the arm connected to the Flush valve.
  • Lift it up and inspect it thoroughly.
  • If there is dirt, use a brush, vinegar, or detergent to clean it off.
  • If it is torn or broken, then you have to replace it.

I know this part is not easy, but you can do it if you stay a bit careful, and your toilet tank not filling issue will be no more.

4. The Fill Valve is Faulty

The Toilet Water Fill Valve is Faulty

Like the flush valve, the Fill valve can also get clogged and prevent the water from filling the tank. As I have explained, the Fill valve is responsible for filling the toilet tank from the water supply until it is full. A Bobber inside the tank controls it.

It is also an easy fix. Open it up, clean it using a screwdriver or something similar, and reassemble it. Or in worst cases, replace it. Here is how to do it.

  • Turn off the water line supply and empty the tank.
  • Rotate the valve to loosen and remove it. 
  • Check the tiny holes of the valve for any debris or blockage. 
  • Use a screwdriver with water and remove all the dirt.
  • Then reassemble it and see what happens.
  • If that does not work, then you may need to replace it.

It is easy to fix as this fill valve may cause the issue of why your toilet tank not filling up with water. Try it and see the results.

5. The Boober or Float is Not Working

The Toilet Float is Not Working

The Boober or Float is a part of the flushing process and rarely is causes the problem of toilet tank not filling. It looks like a soft balloon. It tells the water supply when the tank is full. So that it can stop releasing water into the tank. 

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When the water level rises, the Boober also rises with it, and when it is full the Boober signals the supply line it is time to stop. And when the tank water is low, the bobber signals that I need water. That is how it works.

So if there is any problem with the mechanism of this Boober, like getting stuck or malfunctioning, then it will not able to signal the water supply properly, causing an issue in the tank.

  • To fix this issue, all you have to do is to readjust the Boober and make sure it works as expected. 
  • Get a screwdriver and rotate the screw to raise the ball and water levels. 
  • It should solve the problem. See what happens.

If that does not work, you have no other option than to replace it.

Last Words

So this is how to fix the toilet tank not filling up with water issues at home. First, know how this toilet system works, then know what is causing it, clean it off, or repair it. If you can not, then replace it. You do not need a plumber if you follow the process I explained. But It is recommended to get a plumber if you know nothing about it. I wish you the best of luck.

Toilet Keeps Refilling FAQs

Toilet keeps refilling FAQs

What causes the toilet tank not to fill up with water?

Many things can cause this issue. But the most common problems is disconnected water supply, broken arm handle, faulty fill valve, flush valve issues, boober or float damage, and toilet trip handle issue.

Why is my toilet water tank not filling up?

Because there is a problem in the toilet tank, like valves are damaged, the water supply is closed, or the trip handle is malfunctioning. Fix them, and the toilet will work fine.

How do I know if my fill valve is broken?

If water is not filling your toilet tank properly then know there is a clog in the fill valve or it is broken. Check and fix it to restore water in the tank.

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About Author

Nazim Ali

Nazim Ali is an engineer who loves fixing things at home. He loves to try new things and share the knowledge with the world.