What Is A Flush Valve In Toilet? A Deep Look Into Flush Valve

What Is A Flush Valve In Toilet? A Deep Look Into Flush Valve

Are you wondering what a flush valve is and its function in the toilet? Let’s give you detailed information about this. There is this part inside your toilet tank that releases water into the toilet bowl once activated. This part is referred to as the flush valve in the toilet.

With each flush cycle, the flush valve gives access for water to flow into the bowl so your toilet or urinal can be cleaned. However, when problem arises with your toilet flush valve, it can impede the smooth flow of your toilet. For instance, a continuous leaking or running toilet may likely be caused by a faulty flush valve.

In this article, we’ll give you a deep look into what a toilet flush valve is and other information relating to flush valve.


What Is A Flush Valve In Toilet? A Quick Overview

Flush valve in your toilet is a plastic or brass fitting responsible for the large volume of water released into your toilet bowl when the flush handle is activated. You can locate the flush valve inside the toilet tank or in the body of your urinal.

The flush valve in your toilet usually comes in different sizes that can range from 2 to 4 inches and this will depend on your toilet design.

The major parts of the flush valve assembly consist of the following:

  • Trip lever also known as the handle
  • Flapper valve
  • Overflow tube
  • Flush valve seat which is the hole at the base of the tank
  • Sponge gasket

Flush Valve Mechanism Of Action

The flush valve in the toilet is located inside the tank and is operated with a flapper or a float ball. This setup sits against the opening of the valve and water is kept intact inside the tank until the flush handle is activated to release water into the bowl.

Also, when the tank is empty, the flapper falls to seal the valve. Now, this allows water to flow to refill the tank for the next flush cycle.

There is this vertical overflow tube that is integrated into the flush valve. This extends from the bottom of the flush valve and up into the toilet tank. You may be wondering what the function of this overflow tube is; well, the role is to prevent water from overflowing the toilet tank. It also allows little amount of water to flow down into the toilet bowl as the tank is filling up.

So, there is a small refill tube that is located at the upper part of the overflow tube. This allows little amount of water to move down the toilet bowl when the tank is refilling. Thanks to this stream of water that moves down the bowl, it replaces the water that usually stands inside the toilet bowl.

So, since we have a good idea of how the flush cycle works, you may experience some problems with how your toilet works and require some repairs.

Below, we’ve listed some likely issues you may face with your flush valve that may be impeding the smooth flow of your toilet.

Likely Cause Of a Malfunctioning Flush Valve

The components of the flush valve can develop issues as time goes on. And these issues can cause internal leaks that you may find it hard to trace the cause. But here are some likely causes why your flush valve may be malfunctioning and leaking:

  • The gasket below the flush valve may be damaged.
  • You may be using the wrong type of flapper.
  • There may be a hole or split in the overflow pipe.
  • Your flapper or tank ball may be worn-out or even flawed. Also, you may have a defective or worn-out seal or disk.
  • There may be issues with the chain that it may get stuck under the flapper or under the ball.
  • There may be corrosion or chipping with the flush valve seat and this can cause the flapper not to seat well.

Tips On How to Fix Your Faulty Flush Valve

Tips On How to Fix Your Faulty Flush Valve

Materials required for your flush valve replacement:

  • Flush valve kit that includes the flush valve assembly (seat, overflow tube, seals, lock nut, sponge gasket, and flapper valve attached to the lift chain).
  • Tank mounting bolts (can require two or three bolts depending on your toilet)
  • Adjustable opening wrench.
  • Flathead screwdriver.
  • Pliers
  • Sponge or towel

If you’ll be replacing your flush valve, take note that it’s recommended you also replace the sponge gasket and tank mounting bolts.

So, to begin your flush valve replacement, turn off the water supply, flush, and use the sponge to wipe the tank empty of water. Lift the lid, then you’ll need to unscrew the tank bolt with the screwdriver and adjustable wrench and lift up the whole tank from the toilet bowl. Then carefully turn it upside down on a rug in order to expose the sponge gasket and the nut holding the valve in place.

Next, pull out the old sponge gasket and unscrew the lock nut. Then disconnect the assembly from the tank and unhook the chain and take out the old flush valve assembly. So, to the new flush valve assembly, slide it into the tank and put the external seal on the lock nut. Use your hand to tighten it then use the pliers to tighten it more. The sponge gasket should be fixed over the locknut

Now, reattach the flapper valve to where the overflow tube is and also attach the chain to the flush lever. Then the tank mounting bolt should be slid into the bottom of the toilet’s tank.

You can now lift up the tank and set it back on top of the toilet bowl. Once the mounting bolt is aligned with the corresponding opening, tighten the lock nut.

You can now restore the water supply and once the tank fills up, flush the toilet. Inspect the water that’s refilled and check for any leaks. If there’s any need for extra adjustment, do so accordingly.

Finally, flush your toilet to test the flush cycle and your toilet should be good to go.

Bottom Line

Flush valve is that essential part of your toilet that keeps the flushing cycle going. This flush valve can make or break your toilet, so getting to know what this flush valve is will help you take the right step whenever you have issues with it.

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