How to Stop Toilet from Running After Flushing

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Does it bother you when your toilet doesn't stop running after a standard flush? Normally, flushing a toilet should be a short, simple and straightforward process. But many homeowners are always challenged with a running toilet.

When your toilet won't stop running after flushing, not only is it a waste of water, but it's also really loud and disturbing. Fortunately, there are simple techniques and tips you can use to stop your toilet from running after flushing.

When you encounter a toilet that won't stop running, start by identifying the root cause. Here are some possible reasons why your toilet keeps running after flush and how you can easily fix these problems:

What You'll Need

  • Replacement fill valve (Tips has been given on how often to replace toilet fill valve?)
  • Toilet flapper
  • Flush valve chain
  • Flush valve
  • Screwdriver
  • Chain locks
  • Rubber gloves
  • Bucket, towel, cloth, or sponge

Check the Overflow Tube

The overflow tube is a hollow that is connected to the flush valve. Its function is to prevent the toilet tank from overflowing if the fill valve doesn't turn off. If this is what's causing your toilet to run after flushing, then do the following:

Check the Water Level in the Overflow Tube

If water is spilling out of the overflow tube, then this is most likely your issue. The water level in the tank may be too high, which is causing water to spill out of the overflow tube and down the drain.

Check the Water Level in the Overflow Tube
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Check the water level by removing the lid from the toilet tank and verifying whether or not the water is too high, causing it to run into the overflow tube. If this is the case, you need to lower the water level. If the water isn't running into the overflow tube, then the flush valve might be the culprit.

Adjust the Float Rod or Float Cup

If your toilet has a float cup, check to see if it's properly positioned. The float rod is the horizontal rod extending from the fill valve to a float ball, while a float cup is a small cylinder that wraps around the fill valve and slides up or down with the water level. If the float cup isn't positioned properly, it may cause the toilet to keep running.

To fix this, locate the screw that attaches the float rod or float cup to the fill valve. Use a screwdriver, a set of channel locks, or pliers to turn this screw about a quarter counterclockwise to lower the water level. Continue making adjustments until the water is no longer flowing in to the overflow tube.

Verify the Overflow Tube Height

If the overflow tube is positioned too low, it will allow water to constantly flow into it. This can be easily fixed by repositioning the overflow tube so that it's level with the rim of the toilet bowl.

The only way to fix a shorter overflow tube is to replace the flush valve. Make sure the new flush valve is compatible with your toilet, and the overflow tube is taller than the old overflow tube to prevent water from draining continuously.

Replace the Toilet Flapper

A toilet flapper is designed to seal the water in the tank. When your toilet is flushed, a chain is used to pull up the flapper, allowing water to flow into the bowl. Once enough water has been expelled, the flapper goes back into its original position to re-seal the tank.

Replace the Toilet Flapper
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If the flapper has decayed or cracked slightly, water will keep flowing out of the tank, and you'll hear the sound of water running. In some cases, the flapper may become dislodged, which will also cause water to leak out constantly. To check if the faulty flapper is the cause of your running toilet after flushing, turn off the water supply and drain the toilet.

Next, carefully remove the tank lid and peek inside your toilet tank. Check if the chain's length is too long or too short, which might explain why the flapper hasn't returned to its original position. If this is the case, then adjust the chain to the appropriate length.

Additionally, a buildup of dirt around the flapper may also contribute to a slow draining toilet. Clean the toilet flapper before taking it back into the position. If you discover it's broken or cracked, then replace it. To replace it, remove the old flapper and replace it with a new flapper that you can purchase from any local hardware store.

Replace the Faulty Fill Valve

A faulty fill is often the cause of a constantly running toilet. It controls water flow into the tank from the main water supply. It's designed to continue filling the toilet until the float arm or float cup reaches the set level. However, a broken valve may continue running non-stop or may even turn on and off inconsistently.

Replace the Faulty Fill Valve
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To verify if the faulty fill valve is the issue, remove the top of the toilet tank and check the set water level and the height of the overflow tube. If the overflow tube is an appropriate height and the water level is set about an inch below the top of the overflow tube, but the water flows continuously, blame the fill valve.

The next solution is to replace it. If you know how to replace the fill valve, then it will be an easy task. You'll need a set of channel locks and a cloth, towel, or a sponge. Start by turning the water off to the toilet with the isolation valve on the water inlet, then drain the tank by flushing the toilet.

You'll find a lock nut securing the fill valve to the toilet. Using an adjustable wrench, remove the lock nut by turning it anticlockwise. Once you're done, you can now reach the fill valve assembly and pull it out from the tank. Take the fill valve with you to local hardware stores near you to find a proper replacement.

After installing your new fill valve, make sure you reconnect the water supply line by tightening the nut clockwise to secure it. Finally, test your fill valve by turning the water supply back on, letting the tank fill with water while observing the water level, and adjusting the float height.

Adjust the Water Level

Sometimes, the incorrect water levels may be the reason your toilet keeps running. If the water level is too high, the tank will constantly refill even after a single flush. On the other hand, if the water level is too low, your toilet may fail to flush at all!

To correct the water level, you'll need to lower the toilet float. You can lower the float ball fill valve by adjusting the screw located on the body of the fill valve. If adjusting the screw doesn't work, you may need to replace your fill valve with a new one that has a lower float.

For a float cup fill valve, reduce the float's height by turning the screw in the same direction. After that, flush the toilet and refill the tank to check the water level. The ideal height should be one inch below the top part of the overflow tube.

Adjust the Fill Height by Checking the Float

The water level in the tank is controlled by an adjustable float. A float that's set too low will lead to a weak flushing toilet, while if it's set high, water spills into the toilet overflow tube, and the fill valve won't shut off. The toilet will keep running.

To learn how to fix the toilet that won't flush, look for the fill level mark on the inside back of the tank and mark it on the toilet overflow tube so you can see it more easily. If you find it, measure down about an inch on the overflow tube and mark it.

After that, flush the toilet and see if water reaches and stops at that mark. If not, and the toilet keeps running, adjust the toilet tank to float up or down. If you have an old toilet, you'll have to bend down the brass rod that connects to the float ball to make adjustments. If it's newer toilets, turn a screw or slide a clip along a rod. Flush the toilet after each adjustment and keep adjusting the float until the water shuts off at the proper level. You can also avoid all these hassles by investing in the best flushing toilets on the market.

FAQs on How to Stop Your Toilet from Running After Flushing

How long should a toilet run after flushing?

It's normal for your toilet to run anywhere from 20 to 30 seconds after flushing. However, if your toilet continues running after you flush it, this could be an indication of a problem with the water tank or other parts of your toilet.

How to fix a toilet that keeps running after flushing?

Whether you're using a corner toilet or dual flush toilet, you should have an idea of what to do when it keeps running. You should also know how they work before resolving the problem yourself. Consider the following if your toilet keeps running.

  • Check the Water Level in the Tank
  • Adjust the Fill Valve or Ballcock
  • Clean or Replace the Flapper
  • Inspect the Chain
  • Check for a Leak

How to stop a continuous flushing toilet?

If your toilet keeps running after you flush it, there could be a problem with your toilet's water tank or other parts. To fix this issue, you should check the water level in the tank and adjust the fill valve or ballcock as needed. If these steps do not resolve the issue, you may need to clean or replace the flapper. Additionally, you should inspect the chain to ensure that it is not tangled or kinked. If your toilet is still running after taking these steps, there may be a leakage somewhere.

Final Thought on How to Stop Your Toilet from Running After Flushing

A running toilet is a headache that nobody wants to deal with. However, with simple tools and some DIY skills, you can quickly fix the problem and enjoy a quiet, water-efficient toilet again. If you are still struggling with a running toilet after trying these steps, consider contacting a professional plumber for help.




Kristina Perrin

Kristina Perrin

Kristina is an expert DIY home remodeler and mom to three. When she's not cooking or experimenting with new recipes, you can find her working on new home improvement projects or writing about her favorite kitchen appliances or DIY projects on Kitchen Infinity blog.

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