What Causes The Toilet Tank Not To Fill Up? (A Step-by-Step Guide)

AvatarByLiana Farrell Toilet Queries

A Running Toilet Can Waste Hundreds of Gallons of Water a Month

A toilet that won’t fill up is a common problem, and it can be both frustrating and expensive. Not only is it annoying to have to keep flushing a toilet that won’t stay full, but it can also lead to a significant increase in your water bill.

In this article, we’ll discuss the most common causes of a toilet that won’t fill up, as well as how to fix the problem. We’ll also provide some tips on how to prevent this problem from happening in the future.

So if you’re tired of dealing with a running toilet, read on for all the information you need to know!

Cause Symptoms Solution
Clogged fill valve The toilet tank does not fill up, or it fills up slowly. Clean or replace the fill valve.
Defective float ball The toilet tank does not fill up, or it overflows. Replace the float ball.
Restricted water supply The toilet tank does not fill up, or it fills up slowly. Check the water supply valve to make sure it is open all the way.
Leaking flapper valve The toilet tank does not fill up, or it overflows. Replace the flapper valve.

Causes of a Toilet Tank Not Filling Up

There are a few common reasons why a toilet tank might not be filling up. Here are some of the most common causes:

  • A clogged fill valve. The fill valve is a small valve located at the bottom of the toilet tank. It is responsible for regulating the flow of water into the tank. If the fill valve becomes clogged, it can prevent water from entering the tank and causing the toilet to not fill up.
  • A faulty float ball. The float ball is a small ball that floats on top of the water in the toilet tank. It is responsible for controlling the flow of water into the tank. If the float ball is damaged or not properly adjusted, it can prevent the tank from filling up.
  • A kinked or damaged supply line. The supply line is the pipe that connects the toilet tank to the water supply. If the supply line is kinked or damaged, it can prevent water from flowing into the tank.
  • A leak in the toilet tank. If there is a leak in the toilet tank, water will be constantly draining out of the tank and preventing it from filling up.

How to Troubleshoot a Toilet Tank Not Filling Up

If your toilet tank is not filling up, you can troubleshoot the problem by following these steps:

1. Check the fill valve. The fill valve is located at the bottom of the toilet tank. It is a small, cylindrical valve with a black cap. To check the fill valve, turn off the water supply to the toilet and remove the cap. Inside the valve, you will see a small diaphragm. If the diaphragm is torn or damaged, the valve will not be able to properly regulate the flow of water into the tank. You can replace the fill valve yourself or you can call a plumber to do it for you.
2. Check the float ball. The float ball is a small ball that floats on top of the water in the toilet tank. It is responsible for controlling the flow of water into the tank. To check the float ball, turn off the water supply to the toilet and remove the lid from the tank. The float ball should be centered in the tank and should be able to move freely. If the float ball is damaged or not properly adjusted, it can prevent the tank from filling up. You can adjust the float ball yourself or you can call a plumber to do it for you.
3. Check the supply line. The supply line is the pipe that connects the toilet tank to the water supply. To check the supply line, turn off the water supply to the toilet and remove the nut that connects the supply line to the toilet tank. Inspect the supply line for any kinks or damage. If the supply line is damaged, you will need to replace it.
4. Check for leaks. If there is a leak in the toilet tank, water will be constantly draining out of the tank and preventing it from filling up. To check for leaks, turn off the water supply to the toilet and flush the toilet. Look under the toilet for any signs of water leaking. If you see water leaking, you will need to repair or replace the leak.

If you have tried troubleshooting the problem yourself and you are still having trouble, you may need to call a plumber to help you fix the problem. A plumber can diagnose the problem and make the necessary repairs to get your toilet tank filling up again.

What Causes The Toilet Tank Not To Fill Up?

There are a few different things that can cause a toilet tank not to fill up. Here are some of the most common causes:

  • A clogged fill valve. The fill valve is a small valve located at the bottom of the toilet tank. It is responsible for allowing water to flow into the tank. If the fill valve is clogged, it will not be able to allow water to flow into the tank, and the tank will not fill up.
  • A faulty float ball. The float ball is a small ball that floats on the surface of the water in the toilet tank. It is responsible for controlling the level of water in the tank. If the float ball is faulty, it may not be able to properly control the level of water in the tank, and the tank may not fill up properly.
  • A kinked or damaged supply line. The supply line is the pipe that connects the toilet tank to the water supply. If the supply line is kinked or damaged, it will not be able to properly deliver water to the toilet tank, and the tank may not fill up properly.
  • A leak in the toilet tank. If there is a leak in the toilet tank, water will be constantly draining out of the tank, and the tank will not be able to fill up properly.

How to Repair a Toilet Tank Not Filling Up

If your toilet tank is not filling up, you can usually fix the problem yourself by following these steps:

1. Turn off the water supply to the toilet. This can usually be done by turning the shut-off valve located under the sink or behind the toilet.
2. Remove the lid from the toilet tank.
3. Inspect the fill valve. The fill valve is a small valve located at the bottom of the toilet tank. It is responsible for allowing water to flow into the tank. If the fill valve is clogged, you can try to clean it by using a small brush or a toothpick. If the fill valve is faulty, you will need to replace it.
4. Inspect the float ball. The float ball is a small ball that floats on the surface of the water in the toilet tank. It is responsible for controlling the level of water in the tank. If the float ball is faulty, you can try to adjust it by bending the wire that connects it to the float arm. If the float ball is damaged, you will need to replace it.
5. Inspect the supply line. The supply line is the pipe that connects the toilet tank to the water supply. If the supply line is kinked or damaged, you will need to replace it.
6. Inspect the toilet tank for leaks. If there is a leak in the toilet tank, you will need to fix the leak before you can fix the problem with the toilet tank not filling up.

Once you have repaired the problem, turn the water supply back on to the toilet and test the toilet tank to make sure that it is filling up properly.

Tips for Preventing a Toilet Tank from Not Filling Up

Here are a few tips for preventing a toilet tank from not filling up:

  • Keep the fill valve clean. The fill valve is a small valve located at the bottom of the toilet tank. It is responsible for allowing water to flow into the tank. If the fill valve is clogged, it will not be able to allow water to flow into the tank, and the tank will not fill up. You can keep the fill valve clean by flushing the toilet regularly and by cleaning the valve with a small brush or a toothpick.
  • Adjust the float ball properly. The float ball is a small ball that floats on the surface of the water in the toilet tank. It is responsible for controlling the level of water in the tank. If the float ball is not adjusted properly, it may not be able to properly control the level of water in the tank, and the tank may not fill up properly. You can adjust the float ball by bending the wire that connects it to the float arm.
  • Inspect the supply line regularly. The supply line is the pipe that connects the toilet tank to the water supply. If the supply line is kinked or damaged, it will not be able to properly deliver water to the toilet tank, and the tank may not fill up properly. You can inspect the supply line by looking for any kinks or damage. If you find any kinks or damage, you will need to replace the supply line.
  • Fix leaks promptly. If there is a leak in the toilet tank, water will be constantly draining out of the tank, and the tank will not be able to fill up properly. You can fix leaks by tightening

    What Causes the Toilet Tank Not to Fill Up?

There are a few common reasons why a toilet tank may not be filling up properly. Here are some of the most common causes and solutions:

  • A clogged fill valve: The fill valve is the small valve at the bottom of the toilet tank that controls the flow of water into the tank. If the fill valve is clogged, it can prevent the tank from filling up properly. To fix this problem, you will need to remove the fill valve and clean it.
  • A faulty float: The float is a small, plastic ball that floats on the surface of the water in the toilet tank. The float controls the level of water in the tank. If the float is faulty, it can prevent the tank from filling up properly. To fix this problem, you will need to replace the float.
  • A kinked supply line: The supply line is the flexible hose that connects the water supply to the toilet tank. If the supply line is kinked, it can restrict the flow of water into the tank. To fix this problem, you will need to straighten out the supply line.
  • A leak in the toilet tank: If there is a leak in the toilet tank, it can prevent the tank from filling up properly. To fix this problem, you will need to find and repair the leak.

Here are some additional tips for troubleshooting a toilet tank that is not filling up properly:

  • Check the water pressure in your home. If the water pressure is too low, it can prevent the toilet tank from filling up properly.
  • Make sure that the toilet tank is turned on. The toilet tank may be turned off if you have recently had a power outage.
  • If you have tried all of the above solutions and the toilet tank is still not filling up properly, you may need to call a plumber.

How to Fix a Toilet Tank That is Not Filling Up

Once you have identified the cause of the problem, you can fix a toilet tank that is not filling up by following these steps:

1. Turn off the water supply to the toilet. This can be done by turning the shut-off valve located under the sink or behind the toilet.
2. Remove the lid from the toilet tank. This is usually held in place by two screws located on the top of the tank.
3. Inspect the fill valve. The fill valve is the small valve at the bottom of the tank that controls the flow of water into the tank. If the fill valve is clogged, you will need to remove it and clean it.
4. Inspect the float. The float is a small, plastic ball that floats on the surface of the water in the tank. The float controls the level of water in the tank. If the float is faulty, you will need to replace it.
5. Inspect the supply line. The supply line is the flexible hose that connects the water supply to the toilet tank. If the supply line is kinked, you will need to straighten it out.
6. Inspect the toilet tank for leaks. If there is a leak in the toilet tank, you will need to find and repair the leak.
7. Replace the lid on the toilet tank.
8. Turn the water supply back on to the toilet.

Once you have completed these steps, the toilet tank should be filling up properly. If the problem persists, you may need to call a plumber.

In this article, we have discussed the most common causes of a toilet tank not filling up. We have also provided tips on how to troubleshoot and fix the problem. If you are unable to fix the problem yourself, it is best to call a plumber.

Here are the key takeaways from this article:

  • A toilet tank not filling up can be caused by a variety of problems, including a clogged fill valve, a faulty float, or a leak in the tank.
  • To troubleshoot the problem, you will need to inspect the fill valve, the float, and the tank for leaks.
  • If you are unable to fix the problem yourself, it is best to call a plumber.

By following the tips in this article, you can help ensure that your toilet tank is always properly filled and functioning properly.

Author Profile

Liana Farrell
Liana Farrell
Liana Farrell is the owner of toiletty.com. She is a mom of two and is very passionate about home improvement.

Liana has ten years of home improvement experience, and in her own words, she said: “I love improving the home, and I’m very passionate about keeping the home in the best possible condition. I love it!”

Liana Farrell balances beauty and functionality when she goes about her home improvement jobs.