Informational Guide

How To Adjust Toilet Float (Beginners Guide)

Wondering how to adjust a toilet float ball valve? With the right advice it’s incredibly simple, just follow our step-by-step guide.

by Matt Moran

A toilet float, sometimes referred to as a ballcock or float valve, is a piece of equipment that allows you to fill your toilet without it overflowing. Every toilet has a toilet float, but it must be adjusted correctly, so you have the right level of water in the tank. 

Too little water and you won't be able to flush your toilet, but too much can lead to overflowing and leakage.

Adjusting a Cylinder Toilet Float

  • 1
    Remove the lid from the tank
    To adjust your toilet float, start by opening up your tank. Your float should be fitted to the shaft of the fill valve inside the system. Lay some rags or newspaper sheets down, and then gently remove the lid and lay it down.
  • 2
    Turn off the water supply
    Find the shut-off valve at the back of your toilet and turn the knob clockwise. This should stop any new water from coming in so you can flush the toilet to empty it.
  • 3
    Identify the adjustment stem on the side of the float
    The adjustment stem is a long tube connecting into a larger valve. This is used to increase or decrease the tank's water level and should be simple enough to find.
  • 4
    Adjust the release clip on the float
    A release clip should be found on the float. By unclipping and sliding the float up and down, you can increase or decrease the level of water in the toilet.
  • 5
    Raise or lower the float 12 inch
    Move the float to the correct level by raising it or lowering it by about ½ inch. You won’t need to go any higher or lower than that.
  • 6
    Test to confirm the process.
    Before replacing the lid, turn the water flow back using the shut-off valve at the back of the toilet and then flush the toilet. If it's all working correctly, then replace the lid. A full guide to adjusting a cylinder toilet float can be found here.
  • 1
    Lift the lid off of the tank and set it aside
    Lay out some rags or newspaper, lift the lid gently from the toilet, and place it on the floor.
  • 2
    Check the water level inside the tank.
    Look inside the tank and see where the water is going up to. It should rest 1 or 2 inches from the top of the tank, but often there's a mark to tell you exactly where it should lie. If the water is higher or lower, then the float is likely off balance and needs to be adjusted.
  • 3
    Turn off the water supply
    Use the shut-off valve behind the toilet to turn off the water supply to the toilet.
  • 4
    Check the float and fill valve
    First, check the whole system to see if there are any issues. If there are, you should call a plumber for some professional help to replace parts. Check the ball float height. If it's working correctly, it should be at the same height as the water. If not, then it's off-balance. Shake the ball float to check if any water has got inside it; if it has, then you will need to replace it.
  • 5
    Use a screwdriver to raise or lower the float height.
    A screw can be found at the top of the ball float. By turning it one full rotation clockwise, you will raise the level; counterclockwise will reduce the level. Keep adjusting until you have it correctly set.
  • 6
    Flush the toilet to confirm the process
    Once you've finished, turn the water back on and flush the toilet. Check for where the water level gets to and where the ball float reaches. If it's all working correctly, then gently replace the lid on top of the toilet.

When Should You Adjust Your Toilet Float?

  • Toilet tank keeps running/filling
    Generally, if your toilet tank keeps running, it's because your toilet float is set incorrectly. This means that your water valve isn't being triggered to close, so water keeps pouring in. Read more about how to fix a running toilet.
  • Toilet bowl doesn’t refill after a flush
    If your toilet bowl isn’t filling to the right level, your toilet float is probably set incorrectly. This means it isn't floating upwards and triggering your water valve to open and allowing water to run in.
  • Flushing the toilet doesn’t clear it properly
    If you have a weak flush, then it’s likely that your float needs to be adjusted because there isn’t enough water in the system. Fixing this will help stop the inefficiency of having to flush twice every time.
  • Toilet tank is taking too long to refill
    This is often caused by mineral deposits blocking your value, but it could mean that your float isn’t operating correctly to open the valve and let water in.

How Do Toilet Floats Work?

Toilet floats exist to regulate the amount of water in a tank, preventing overflow but ensuring there is enough water so it can flush. They do this by controlling the water valve, starting or stopping water flow into the tank.

As the water flows into the tank, the toilet float rises. Once it reaches a certain level, it will trigger the valve and stop water from flowing in. Similarly, when the water is emptying, the toilet float will go down and will close the water valve. Typically, toilet floats are made from durable materials like plastic, chrome, or silicone.

How To Adjust Toilet Float Valve

Two Main Types Of Toilet Ballcocks

  • Cylinder Float
    Cylinder floats were developed in the 1950s and are now generally fitted as standard in most toilets. These are fitted directly to the shaft within the mechanism and rise and fall with the water level. Cylinder floats are easier to adjust, remove and replace than the old school ball float style.
  • Ball Float
    The name ballcock comes from the original ball float, and they are the old-school method used in toilets. You'll find ball floats in older toilets, particularly where the water comes in from the base. These are generally outdated now and don't fit with modern plumbing codes, so you should probably consider replacing them if you can.

Adjusting Toilet Floats for Specific Brands

Every manufacturer of toilet floats has a slightly different model, some of which will need to be adjusted in a particular way. We’ve put brief guides below for all the major models, but make sure you refer to the manufacturer’s manual and follow the instructions there to avoid any issues.

  • Open the toilet carefully
  • Turn off the water supply using the shut off valve
  • Locate the metal valve adjustment clip
  • Use pliers to squeeze it and raise it up or down as needed. Up will increase the amount of water and down will decrease it
  • Put the water back on and perform a test flush
  • Put the lid back on the toilet
  • Remove the lid of your toilet carefully
  • Turn off the water supply and leave to see if the water level is decreasing
  • If the water level is decreasing, you may have a faulty flapper, causing your valve to open. This will need to be replaced.
  • If not, check the level of your float to see if it needs adjusting.
  • A common issue in Korky toilets is the float sticking. Check to see if there is any visible build-up of minerals on the outside of it and wash off if possible
  • Use a screwdriver to adjust the height of the float
  • Turn the water back on and test the system
  • Carefully replace the lid of the toilet if it’s all working correctly

To adjust a Fluidmaster toilet float, you’ll need to:

  • Remove the lid of your toilet
  • Check the level of the water and the float level
  • If they are not, flush the toilet and while refilling, turn the adjustment screw on top of the float to adjust the height. This can be done by hand
  • Turn the adjustment screw clockwise to raise the water level and anti-clockwise to lower it
  • Once adjusted, flush once more to check the level and replace the toilet lid
  • Remove the lid of your toilet
  • Look for the ball float; American Standard only produce one type
  • If it is not at the same level as the water in the toilet, flush the toilet and then adjust the screw on the top of the float to move it up or down while it’s refilling
  • Turn the screw clockwise to raise the water level and anti-clockwise to lower it
  • Once adjusted, flush once more to check the level and replace the toilet lid
How Adjust Float In Toilet Tank


Why does my toilet float stick?

Sticking toilet floats lead to the float staying down and causing excess water to pour into the tank. This can lead to leakages. This is often caused by a poor fitting where the toilet float is catching on the cistern, but it can be caused by mineral deposits building up on the float over time. Fix this by loosening the parts of the toilet and cleaning the ballcock.

How do I raise the water level in my toilet tank?

To raise the water level, you’ll need to adjust the toilet float. This is typically done by turning the adjustment screw clockwise a few turns or by sliding the adjustment clip up.

How often should you replace the toilet fill valve?

You should look to replace your toilet fill valve every 5 years.

Can a toilet float go bad?

Yes. If your toilet will not go to the right level even after an adjustment, then your toilet float is likely broken and will need to be replaced.

How long does it take to adjust a toilet float?

It will typically only take a few minutes to adjust a toilet float, providing you have all the right equipment.


Like a lot of plumbing equipment, toilet floats are essential to day-to-day life. Having them adjusted correctly is the key to an efficient toilet and can save you a lot on water bills in the long run.  

Make sure you look for the tell-tale signs that it needs to be adjusted and, if needed, follow this guide to do it correctly.

Matt is a freelance writer, English graduate, & keen traveler from the UK. As a specialist plumbing expert, he enjoys writing about everything there has to do with at-home plumbing products & related problems. When he isn’t writing, he’s usually drinking coffee or planning his next adventure. In his spare time, he also runs his own blog all about digital nomad life.