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Toilet Still Running After Water Turned Off

Shutting your toilet’s water supply off is something you might have to do before repairs. You might also turn the water off to check for a leak.

If you notice that water is still running when the valve is off, there are a few steps you can take to fix the problem.

Toilet Still Running After Water Turned Off

Is your toilet still running after the water is turned off? The most likely reason is a faulty valve. It might be possible to fix the problem by replacing an old washer, but you might need to replace the valve.

Turning Off the Water Valve

Before going further, make sure you turn off your toilet’s water supply.

There are two connections between a toilet and your plumbing system. The first one is the flange. The flange is the large opening at the bottom of the unit or in the back. The purpose is to flush waste into the sewer system.

The second connection is the water supply line. This line brings fresh water to the unit so you can flush. You’ll find the water valve on this supply line. It runs on the left of the toilet. The valve should be near the point where the supply line enters the wall or the floor.

In its open position, the valve acts as a part of the supply line and lets water through. When you close the valve, its internal component becomes perpendicular to the water supply line and blocks water.

You might have to use force to close your toilet valve. Most people don’t shut off the water to their toilet regularly, which can make the valve difficult to move.

Empty the Toilet Cistern

The cistern is the part of the toilet where you’ll find the water tank and flushing mechanism. Before thinking about fixing the valve, make sure the tank is empty.

Your toilet can keep running because there is still water in the tank. It can take a while for the tank to empty, especially if you have a faulty flapper.

The flapper is the component that opens and lets water out of the tank when you flush. If your flapper doesn’t form a tight seal when closed, your toilet will run. A simple trick to check the flapper is to add a few drops of food coloring to the toilet tank. Wait a few minutes to see if the water in the bowl changes color. If it does, you need to replace the flapper.

After shutting off the water valve, flush your toilet to empty the tank. Most modern units have a tank capacity of 1.6 gallons. Older models will hold more and might need more than one flush.

Flush your toilet two or three times to empty the tank and get rid of any water left in the upper portion of the supply line.

Open the Toilet Cistern

Next, you should check the toilet tank. Some models have a lid or cover that you can lift to access the flushing mechanism.

Toilet Cistern

Others have a sealed cistern. It’s the case with dual-flush toilets. You can open the cistern with a few simple tools:

  • Push one of the flush buttons down and look for a small indent on the side of the other button.
  • Insert a flathead screwdriver into the indent. Push until the button pops out.
  • You can then remove the other button.
  • You’ll see a screw at the bottom of the button receptacle. Remove it.
  • You can then lift the receptacle and open the cistern.

Now that the cistern is open, you can check whether water is coming in. If you can see the tank filling up slowly even though you have closed the valve, you have a faulty valve.

You might also find that the water is off, but your toilet is running because of a faulty flushing mechanism. Use a small container to manually empty the tank to see if your toilet stops running.

Replacing the flushing mechanism is a simple repair. The steps will vary depending on the model you have. It’s best to visit your toilet manufacturer’s website to find replacements and instructions.

How To Replace a Faulty Toilet Water Valve

If you’re having issues with a toilet still running after water is turned off, your best option is to replace the valve.

The good news is that you might only have to change the washer. Washers are small rubber bands that prevent leaks. They form a tight seal around pipe fittings and other plumbing connections.

Because most people don’t use their water valves often, the washers can rot. With water bills ranging from $20 to over $100, bad washers can become a costly issue.

You’ll have to remove the valve, check the washers, and replace them if needed. You can also assess the state of the valve and install a new one. The steps to follow are the same, and you won’t be able to check the washers until you have disconnected the valve. Since water valves aren’t expensive, it’s best to buy this part before you disconnect the old valve even if you end up only replacing the washers.

Before you get started, you’ll have to turn off the main water valve. Next, you should drain water from your plumbing system.

The trick is to turn on a faucet that is lower than your toilet. Your outside garden hose faucet might be a good option. Have a bucket ready since there might be water left in the supply line.

Use a crescent wrench to remove the bolt that connects the water supply line to the toilet. Empty this line and use your wrench to disconnect it from the faulty valve.

You can then shine a flashlight into the valve and look for rust, clogs, or damaged washers. Disconnect the bottom of the valve with your wrench.

How To Replace a Faulty Toilet Water Valve

At this point, you can change the washers, reconnect the old valve, and see if your toilet keeps running. You might also be able to fix the problem by cleaning the inside of the valve.

You can also discard the old valve and install a new one. Use your wrench to connect it to the water supply line and to the line that runs to the toilet unit. Turn the water back on to test the new valve.

Tips for Getting the Valve Off

Getting the bolts off the valve can be difficult. These bolts are likely to rust since bathrooms are humid and most people don’t use these valves often.

You can scrape visible rust if the bolt isn’t moving. You can also apply more torque with a battery-powered wrench. If the bolt is not coming off, use a rust remover product.

When To Call a Professional

Replacing a faulty water valve is easier if you have PVC plumbing. If you have older iron or copper pipes, it might be best to call a professional.

In older homes, plumbers would often solder the toilet valve to the water supply line (if you’re wondering if it’s possible to fix your toilets water supply line through the floor, read here). You can remove it with a pipe cutter, and it’s possible to install a new valve with some bolts instead of soldering it.

This process requires some specialized tools. Plus, cutting through metal can be difficult if you lack experience.

It’s best to call a professional if you have an old plumbing system or don’t feel comfortable working on plumbing.


Is your toilet still running after the water shuts off? You probably need to replace the water valve or at least put some new washers in it. Before you replace the valve, make sure to completely empty your toilet tank to make sure the issue comes from the valve.

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