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Toilet Shut-Off Valve Won’t Shut Off: 7 Reasons & Solutions

A bad shut-off valve is an emergency and should be dealt with immediately.

It’s because it can cause different problems.

But the thing is sorting out the reasons for it and getting the solution. 

Why your toilet shut-off valve won’t shut off?

The first thing that should come to your mind is that something is blocking it. It can float or kinks in the supply line. Sometimes the valve from the main water line contradicts your toilet’s shut-off valve. Or you might have a broken lever to flush the water. 

You won’t be able to flush your toilet like you normally would.You’ll learn how to identify your problem and how to fix it easily.

So let’s get things started!

7 Reasons Why Toilet Shut-Off Valve Isn’t Shutting Off With Solutions

A bad shut-off valve is crucial and should be dealt with immediately. There can be a lot of reasons behind it not shutting off. I’ve tried to pin down the most likely possibilities. I also tried to provide you with the easiest solution.

Reason 1: Float Stuck in Water Line

It’s possible that a float has been caught on top of the incoming water line. This problem will give you symptoms like the water will not shut off. You can’t see the float since it’s stuck on the water line. Or you don’t know that it is stuck. 

This may cause damage to lines and equipment if the water keeps running for too long.

You won’t be able to use your toilet in the way you’re used to. When you flush, the water will keep coming out of the tank into the bowl. And it will never stop draining until you take action.

The float might even leak onto your floor. Maybe a corroded zinc top that by itself is flimsy and weak.

This problem occurs when the float has become stuck in between the incoming line. And it overflows the tube of your toilet tank.


Flush your toilet after turning off the water. Then turn on the water once more to see if the problem is resolved. If not, call a plumbing service.

Reason 2: Kinks in Supply Line

If you have any kinks in either of your supply lines coming up from under your toilet bowl. For symptoms, you can look out for yellow water lines coming up to the bowl. You might see that the water is not shut off when you turn the valve on.

The reset button might not work, no matter how hard you push or pull the handle. You can turn the knob and yet your shut-off valve won’t open or close. 

You can see that no water flows out of the hose faucet(if there is one). If there is water flowing, it is leaking out of the drain pipe. If water flows at all, it runs too far before stopping


To fix this, first, turn the water off at the main shut-off valve. Note that you should first use a cut-open tube to turn off the water. Before turning off other valves in your house. It’s to avoid flooding your house if there is an unexpected shut-off in your city supply line.

If you do not have enough hand pressure then turn on a faucet. And let some water flow out of both supply lines. Do this until you feel like there are no bends or kinks in the “T” lines. I’m talking about the lines that go from under the bowl to above it. 

Next, turn on all faucets. So that all of your taps can get some water flowing down to the flush valve

Reason 3: Main Water Line Valve Problems

Sometimes the valve in your main water line can imitate your toilet’s shut-off valve. Not all toilets have this. But if you do have this, it’s something to look out for.


The trouble with this one is that it has two flaws. First, you need to replace the valve at the main water supply. Second, the shut-off valve is designed to shut off at just above 14 psi (or 1.5 bar). 

A normal household is around 35-40 psi on average. So if you are using less than 14, replace the entire supply line. Choose the one that provides higher than normal pressure.

This might seem like a minor problem. However, in the long run, it can result in hundreds of dollars in losses. And not to mention the unnecessary stress during emergencies. So, it’s something to look out for. And you never know when that main water line valve will act up again. And shut your toilet off by mistake. About that, the cost of replacing the main water shut off valve is also a big matter.

Reason 4: Toilet Lever Problem

This is if your toilet has a lever at its base. Sometimes you can see that the lever is damaged or broken. Then the shut-off valve won’t shut off. 

Sometimes the lever might not be in its locked position which causes this problem.


If the lever is broken, you just need to get a new one. If you’re having problems finding a good one, here are some suggestions-

Product 1
Product 2

Sometimes there may not be enough water to turn on the valve. But you can fix this by adding more water to fill more of your tank’s level. Until it shuts off automatically when there is enough pressure present in the tank.

Reason 5: Rusty Valve

One of the reasons why your toilet shut-off valve isn’t shutting off is rust. This happens mainly due to the type of parts that are being used on the valve.

The issues with this problem could be in the ballcock or float ball. The ball of the toilet should be adjusted perfectly. These parts are the ones responsible for opening and closing the valve. This part is made up of a rubber ball, which is held together by a metal shaft. And a bracket keeps it together. 

These parts are usually held together with old age and exposure to rust.

The symptom to identify this problem is if you have visible rust on the valve. This type of problem might be more common in older homes. Because they used copper pipe instead of plastic pipe.


First, you’ll need to take apart your shut-off valve before trying to find out what’s wrong. You’ll need to replace the rusted portions of the shut-off valve to solve this.

It’s not just a matter of replacing these parts by themselves. There’s also something you should think about to deal with this problem. And that’s cleaning up your water pressure.

Reason 6: Broken or Damaged Valve

Your valve can get damaged due to several reasons. Due to this the handle of the water valve can get broken.

Heavy wear and tear is the main reason behind this. When you flush the toilet, the rushing water from the tank can cause damage. It has the potential to break off pieces of the valve. It’s bad because they control the flow of water from the tank.

Hands with wet skin touching a metal surface could corrode it. This can cause the rust to set in. Corrosion can also happen if you use harsh chemicals when cleaning your toilet bowl. So beware of this before flushing. 

The wrong type of valve installed on your toilet shut-off valve can do damage as well.


All you have to do to solve this is replace your old valve with a new one. If there’s a leak, then you need to repair the toilet shut-off valve by adding new valves. Make sure that you use the right tools when doing this to avoid causing further damage.

Reason 7: Partially Closed Valve

Sometimes your toilet shut-off valve will partially close. This is related to the accumulation of scale.. Scale is actually a natural mineral deposit that sticks to the inside of a metal pipe. This happens as its water passes through. 

This buildup can happen anywhere in your plumbing system. And if it piles up sufficiently, your toilet shut-off valve will become unable to close. 


You need to clean your toilet shut-off valve with a toothbrush and some mild dishwashing soap. Wait until you get the scale off and then shut off the water to your house. 

If that fails, try using a wire coat hanger. Then insert it into the pipe where your toilet shut-off valve is installed. You’ll be able to siphon out the build-up of mineral deposits. This should clear things up for you.

There you go! Hopefully, this has helped fix your toilet shut-off valve problem. You won’t have to worry about forgetting to turn it off when you leave the house.


How long does it take for the water to cease flowing once you turn off the main valve?

It may take a few minutes for the water to stop flowing completely. As you turn the valve clockwise, it will close. The volume of water that passes through will be reduced as a result. And ultimately stop it.

What is the lifespan of water shut-off valves?

A shut-off valve should endure between 10 and 25 years. That’s a 20-year average. However, they should be used every year or two. Otherwise, there is a considerable probability that one of the valves would freeze.

How much does it cost to replace a shut-off valve?

A water shut-off valve normally costs between $375 and $600 to replace. However, the cost might be as much as $800 or more. This is determined by the location of the valve, and the type of valve.

Winding Up

So here we are! Now you should know what to do if your toilet shut-off valve won’t shut off.

Sometimes you can see that the valve appears to work just fine. But you get no flow. Then check for possible blockage in your toilet bowl.

Best wishes!