How Long Should It Take To Fill A Toilet Tank? (Find Out Now!)

Jessica Stone
by Jessica Stone

Have you noticed that the water in your toilet takes a while to fill after you’ve flushed? You’re not alone. In fact, this is a common issue among homeowners and there are several reasons why this problem can occur. The time that it takes for a toilet tank to fill will vary based on the design and size of the tank, which may be from 1.6 to over 7 gallons.

Flushing takes approximately 10 to 15 seconds, while refilling the tank usually takes between 45 seconds to 1 ½ minutes. However, depending on your water pressure, it’s not unusual for the tank to refill in about three minutes.

With these time frames in mind, you may be wondering why your toilet is taking longer than normal to fill and what you can do about it. While none of the causes of this issue are especially problematic or expensive to fix, identifying the problem will help you apply the proper solution to have your toilet back up and running optimally again as quickly as possible.

Continue reading for the most common causes of a slow-filling toilet tank, how to effectively troubleshoot the problem, and the actionable steps you can take to correct it.

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How Long Should it Take to Fill a Toilet Tank?

The exact time that it should take for a toilet tank to fill up will depend on the specific size of the tank and the water pressure in your home. With the proper amount of water, the average time that a toilet tank takes to fill is about three minutes. Though it may take between 45 seconds and 1 ½ minutes, depending on your toilet and the conditions in your home. Some models take as little as 25 seconds to fill up.

However, if your toilet tank takes more than three minutes to fill, this is a strong indication of a problem. There are a number of factors that can disrupt the pressure of the water that enters the container – from the age of the valve to debris stuck in the system. Over time, debris can build up in the system, shut-off valve, and supply line creating a clog that results in a drop in pressure.

Why Is My Toilet Tank Slow to Fill?

If you notice that your toilet tank is taking longer to fill than normal, you may have an issue that requires your attention. Generally speaking, there are three main reasons for this problem:

1. Water Supply Valve

The water supply valve is the knob that juts out of the wall right below your toilet tank. This valve is responsible for controlling the water that flows into the tank. Whether it’s partially closed or not functioning properly, this can cause the valve to no longer be able to provide the proper amount of water at the appropriate speed.

A partially open supply valve is one of the most common reasons that people have a slow filling toilet tank. Though, another potential issue with the valve could be a buildup of debris. This will restrict the flow of water and hinder the valve’s filling speed.

Troubleshooting Tip: Start by checking to see if the valve is completely opened. If the valve is open and you’re still having issues with your tank refilling speed, you’ll want to contact a professional plumber to evaluate the valve for debris buildup.

2. Waterlogged Float Ball

If you’ve ever taken a look inside of your toilet tank you’ve likely seen a float ball sitting on the top of the water. This float ball is designed to control the amount of incoming water. If you have a float ball that is waterlogged, it cannot let the tank fill properly. This problem prevents the appropriate amount of water from entering the tank. Or, it will cause the water to fill at a slower rate.

Troubleshooting Tip: Take off the toilet tank lid to inspect the water level. If it’s only partially full or you notice that the ball is not floating at the top, you could have a waterlogged float ball. Fortunately, correcting this problem is as easy as replacing the float ball with a new one by pulling the old one off of the float arm. It’s important to note that float balls are old toilet technology and if you notice that this mechanism has gone bad, it’s worth looking into having your toilet’s interior parts replaced with more modern components.

3. Fill Valve Tube

Inside of the tank, attached to a vertical tube-shaped component, you’ll find the fill valve. The fill valve’s purpose is to control the level of the water in the tank. Over time, these valves can get worn out, become clogged, or shift out of the proper alignment. Any of these problems can lead to the issue of your toilet tank not filling properly.

Troubleshooting Tip: If you’ve determined that the issue isn’t caused by a waterlogged float ball or your water supply valve, you’ll want to take a closer look at the fill valve. Inspect it for any signs of wear or improper positioning. In most cases, the fill valve will be mounted on the left side of the toilet tank and have a tailpiece that protrudes through the base of the tank and attaches to the shut-off valve and supply tube.

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Fixing a Slow-Filling Toilet Tank

Now that you should have a better idea of what might be causing your toilet tank to fill slowly, follow these steps to correct the issue:

  • Start at the water supply valve, making sure that it’s completely open to allow for maximum water flow. If it’s not, this may be the cause of your problem.
  • If the water supply is already fully open, try cleaning both the valve and the pump. Sediment may build up over time and a good cleaning could correct the issue.
  • Adjust the float ball. If you notice that the float ball is waterlogged, you may be able to fix it by adjusting the arm. Bend the float arm upward slightly so that the ball sits higher in the tank and allows for more water to flow in.
  • If bending the arm doesn’t fix the problem, you may need to replace the float ball. You can purchase a replacement or contact a local plumber to upgrade to a newer style mechanism.
  • Adjust the fill valve. Locate the fill valve on the left side of the tank and make sure that it is evenly and securely attached to the tube. Verify that the water level is about an inch below the overflow tube. For older toilets, use a screwdriver to loosen the adjustment screw and lift the fill valve to allow more water in. For modern toilets, turn the fill valve adjustment knob manually to let more water in.
  • Disassembling and cleaning the fill valve may also correct the problem, if nothing else has worked so far.
  • To correct a clogged valve tube, you need to clean the debris in the tube. Start by shutting off the water supply, then remove the hardware from the valve and use a slim brush to clean out the tube. Open and close the water supply valve a couple of times to flush away any remaining debris.
  • If the tube has tears, holes, or looks damaged, you’ll want to replace the valve tube.

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Jessica Stone
Jessica Stone

Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.

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