How to Adjust Toilet Fill Valve

There are a lot of components that come with the toilet you have in your washroom. But you will get only two things with the toilet tank. One is the flush valve and another is the fill valve. Also known as the ballcock.

If you have proper knowledge about these parts, you can easily fix and adjust these parts by yourself. And save the money of the plumber. It’s good to learn new DIY plumbing skills and apply them in your daily life.

Difference between the flush valve and the fill valve

How to Adjust Toilet Fill Valve

Basically a flush valve ensures you a proper flush. Flush valves release the water that was stored in the tank to the toilet bowl when we press the flush button.

The work of the fill valve is to control the water flow that fills the tank after you use the flush. It also adjusts the water level in the flush after flushing. It is quite obvious to adjust the fill valve to get the premium performance from your toilet. The main reason behind you having to adjust the fill valve is sometimes the toilet fails to flush properly.

It’s because of insufficient water stored in the tank. And sometimes the water level goes up to the overflow tube. So you have to adjust the fill valve to fix the problem. If adjusting doesn’t work, then you should get a new toilet fill valve and replace the old one.

Different types of fill valves have different types of methods to fix the problems. So you have to find what type of filling valve you are using and then check out “how to adjust the fill valve” section to fix the problem.

Types of toilet fill valves:

Different toilet models come with different types of fill valves. It’s important to know the name of the different types of fill valves. It will help you to know more about these valves.

The name of these types are –

  • Plunger/Piston Ballcock
  • Diaphragm Ballcock: Brass
  • Diaphragm Ballcock: Plastic
  • Float-Cup Fill Valve
  • Internal Float Fill Valve
  • Adjust a Floatless or Pressure-Activated Fill Valve

How to adjust a toilet fill valve

1. Adjust a Plunger/Piston Ballcock:

Nowadays this type of fill valve is rare. New toilet models don’t come up with these types of fill valves anymore. But there are some old toilet models that still work that are dependent on this mechanism of the fill valve.

This plunger/piston fill valve operates with a floating boat that is attached with a horizontal brass float rod. The rod moves a plunger or piston from bottom to top in the ballock body to control the water flow in the tank. This type of mechanism is known as ballock. This mechanism design uses an o-ring to make a seal to stop the water flowing over the top of the fill valve.

Adjust the water level

  • If you want to increase the water fill level then bend the float rod upward gently.
  • You should keep the water level below the top of the overflow tube of the tank.

2. Diaphragm Ballcock: Brass

A diaphragm Ballcock is almost the same as the plunger style. But the major difference is this valve uses a diaphragm seal inside a round valve body in the place of using a plunger stem. The water discharges control with a float rod and ball. This makes this mechanism a true ballcock.

This type of fill valve assembled after the classic plunger style. You will not have this mechanism in new toilets. Some old toilet models still have this type of fill valve.

Adjust the water level

  • Bend the grass float rod upward gently if you want to increase the water fill level. And bend the rod downward to lower the water fill level.
  • The water level must not cross the top of the tank’s overflow tube.

3. Diaphragm Ballcock: Plastic

There is a plastic version of the old diaphragm ballock which is made of brass.

You will find an adjustment screw on the top so that you can adjust the height of the float rod and the ball. This valve is also called the true ballcock. You can still find this kind of unit in the market. But now the float-cup style fill valve replaced the Plastic diaphragm Ballcock.

Rotate the Screw Clockwise or CounterClockwise

  • Rotate the screw to increase the water level to increase the water level. And rotate the screw anti-clockwise to decrease the water level.
  • Keep the water level below the top of the tank’s overflow tube.

4. Adjust a Float-Cup Fill Valve

Nowadays new models of the toilet use a float-cup fill valve. This type of fill valves are modern. Its low price and durability makes it popular. a cylindrical plastic float controls the water flow. There is no traditional float rod and ball so it’s called a “floatless fill valve”. You will find a metal spring clip to a thin metal rod attached with the floating cup that controls the fill valve.

Pinch Ends of Metal Spring Clip

  • Compress the both ends of the metal spring clip to raise or lower the float.

Adjust the water level

  • You must keep the water level 1 inch below the top of the tank’s overflow tube.

5. Adjust an Internal Float Fill Valve

There is a new type of fill valve that appeared in the market called the internal float fill valve. It is also marketed as a Quiet fill. It comes with a hidden internal float lever installed inside the head of the valve.

Turn Top Head

  • To unlock the fill valve, turn the top head anti-clockwise.

Move Valve Up or Down

  • The fill valve moves up to raise the water and moves down to lower the water.

Turn Top Head Back into Place

  • Turn the top head back to lock it into the place

6. Adjust a Floatless or Pressure-Activated Fill Valve

The most innovative fill valve found in the market is Floatless or Pressure-Activated Fill Valve. It uses a pressure-sensing mechanism to adjust the water level in the toilet. This valve operates under the water. It can also sense the water level based on the pressure.

Rotate Adjustment Screw Clockwise or Counterclockwise

  • The adjustment screw is located on the top of the valve. You have to rotate the adjustment screw clockwise and anti-clockwise to raise and to lower the water level.

Check the water level

  • Keep the water level below the top of the tank’s overflow tube.

Final word

We try to give you all the information about how to adjust the fill valve of your toilet. We hope you can use the knowledge in practical life, can adjust your toilet fill valve without calling a plumber and save a couple of bucks for your family.

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