How to adjust the water level in the toilet tank

The water level in the toilet tank, whether high or low, may not seem like a significant issue at first, but over time, it can cause problems. If there isn’t enough water in the tank, the flushing power won’t be strong enough, leading to a clogged toilet. On the other hand, too much water can cause the toilet to overflow or fail to flush completely. Fortunately, these issues are not difficult to fix. The height of the float can be easily adjusted with your hands or a screwdriver in just a few minutes, and there’s no need to hire a plumber.

Lift the toilet tank lid. Remove the lid from the toilet tank and set it aside. Now, you have access to the internal mechanisms of the toilet tank. Be cautious not to drop the lid and avoid placing it in areas where it might fall. The tank lid is made of porcelain and is quite fragile.

Monitor the water level in the tank. The water level should be 2.5-5 cm lower than the fill valve and overflow tube (the large tube near the center of the tank). If the water level is above or below this range, the tank is not balanced.

• Your toilet may have a marked line inside the tank, either printed or etched into the ceramic, indicating the proper water level setting.

Turn off the water supply to the toilet tank. Locate the water supply valve, typically on the wall behind or beneath the toilet. Turn the knob fully clockwise, then flush to drain all the water from the tank. Once emptied, the tank will not refill. This allows you to work inside the tank without interference.

• Keep turning the knob until you hear the water stop flowing.
• Do not attempt to adjust or repair anything inside the toilet tank before flushing all the water out.

Inspect the float and fill valve. Examine the flushing mechanism to assess its overall condition. If any damage or defects are found, it may be necessary to call a professional plumber for repairs.

Check the float height. Look at the float inside the tank, which is a plastic ball attached to an arm above the fill valve. The float height determines the water level after refilling. It should align with the marked line if functioning properly. If the float appears too high or too low, adjust its height and check the water level after the tank refills.

• If the float is higher or lower than the mark, this could cause excessive or insufficient flushing.
• Shake the float. If you hear water sloshing inside, the float needs replacement.
• Ensure the float is properly connected to the fill valve.

Use a screwdriver to adjust the float height. On top of the fill valve, you’ll find a screw directly attached. Turn the screw one full rotation either clockwise or counterclockwise. Turning clockwise will raise the water level, while turning counterclockwise will lower it.

• Avoid turning the screw more than one full turn at a time, as too much adjustment can cause uneven flushing.
• If the screw is rusted and immovable, simply adjust the float. The float is screwed into the arm connected directly to the valve.

Flush the toilet to check the water level. Turn the knob to allow water to fill the tank and wait for 1-2 minutes for the tank to fill up. After flushing the toilet, observe the water level. Ideally, the water should be about halfway up the tank. If the water level is still too high or too low, flush the toilet again and adjust the float until the water level is at the desired height.

• Call a repair technician if the water level does not reach the correct level after multiple adjustments.

Identify the cylindrical float. Some newer toilet models are equipped with a modern solid float (sometimes called a float cup) instead of the traditional arm-and-float design. This float is a cylindrical shape attached to the valve shaft. If your toilet is equipped with a cylindrical float, you can adjust the water level in just a few seconds.

• The cylindrical float is easy to install, remove, and maintain, making it user-friendly even for those with little experience in home repairs.

Open the toilet tank lid. Lift the lid and place it on a flat surface, such as a table. Be careful not to drop the lid or place it near the edge of the table, as toilet tank lids are often made of ceramic and can break easily. After opening the lid, check the water level – if it is higher or lower than the fill valve or overflow tube by 2.5-5 cm, you need to make adjustments.

Turn off the water supply before adjusting the float. Find the water supply valve outside, on the wall behind the toilet or below the tank. Turn the knob fully clockwise. Once the valve is fully closed, flush the toilet to empty the tank.

Locate the adjustment lever on the side of the float. The adjustment lever is a small, long tube that connects to the fill valve. On most toilet models, it runs parallel to the valve or crosses over from the top of the valve. The lever is used to increase or decrease the water level in the tank.

• It is advisable to familiarize yourself with the internal mechanisms of the tank before making any significant changes. Refer to the user manual or the manufacturer's website if available.

Look for a clip attached to the float. Some cylindrical floats are positioned by squeezing a clip attached to the float to raise or lower it to the desired height. Raise the lever to increase the water level and lower it to decrease the water level.

• If the float is equipped with a clip, squeeze the clip to adjust the height of the float. If not, you will need to find the position of the adjustment knob attached to the lever.

Raise or lower the float by about 1 cm. Use your two fingers to grip the adjustment knob at the top of the lever. Rotate the lever clockwise or counterclockwise to raise or lower the float. Once the float is set to the appropriate height, replace the tank lid and turn the water supply back on.

• If you cannot rotate the adjustment lever, look for a slot to turn with a screwdriver. Some adjustment knobs are tightened with screws.
• Avoid rotating the knob more than once each time. If the water level is adjusted too drastically, the toilet may flush unevenly.

Check the water level after turning on the fill valve. Flush the toilet a few times to see if the water level has increased or decreased. The water should be about halfway up the tank. If it doesn't meet the requirement, continue adjusting the float until the desired height is achieved.

• Call a repair technician if the water level does not reach the required height after several adjustments.

Replace the water valve if adjustments aren't working. If the toilet continues to run and adjusting the float height doesn't solve the problem, you need to replace the valve. Replacing the valve requires opening the hole underneath the tank. If you're not comfortable doing more complex tasks in the toilet, it's best to call a plumber.

• The type of valve you'll need depends on the kind of toilet you have. Check online to find out which valve model is compatible with your toilet before purchasing.
• You can also purchase a universal toilet repair kit from a hardware store or supermarket, which includes a valve, float, and flush valve that fit most toilets.

Turn off the water supply and drain the tank completely. To install a new water valve, you'll need to drain the toilet tank. Find the water supply valve outside, either on the back wall or beneath the toilet. Turn the knob fully clockwise and then flush the toilet. Once the water is drained, the tank won't refill. Continue flushing until the tank is completely empty.

• Use a dish sponge or towel to soak up any remaining water inside the tank.

Remove the water valve from the outside of the toilet tank. You'll find two nuts outside the toilet tank. First, loosen the nut connecting the water pipe to the valve. Pull the water pipe away from the valve. Then, unscrew the plastic nut connecting the valve to the tank, which you can usually do by hand. After loosening both nuts, you can remove the water valve from the tank.

• You may need to use a wrench or pliers to remove the nuts.
• Place a towel to absorb any water that leaks out from the disconnected pipe.

Remove the old valve from the tank. Pull out the entire valve assembly, including the float attached to it. The valve will come out as a single piece. Discard the old valve unless you plan to have it repaired by a professional.

• Handle everything carefully to avoid damaging or loosening any other parts inside the tank.

Install the new water valve into place. Insert the base of the valve through the hole at the bottom of the tank. The remaining part of the valve will stand upright once it's installed. The valve must be securely attached and not wobbly or movable. Make sure the valve is firmly connected to the bottom of the tank before reassembling the toilet.

Reconnect the water supply pipe. Attach the water supply pipe to the valve's base, and use washers to securely connect the small water supply pipe to the bottom of the toilet tank. Tighten the plastic nut to prevent leaks when you turn the water supply on.

Turn on the water supply and test the toilet flush. Locate the water supply valve on the outside of the tank and turn the valve clockwise to open the water flow. Flush the toilet several times to check the new water level.

• It's also important to check the shut-off valve and the base of the new valve. Clean the area and check for any water leaks, tightening the connections if necessary.
• If the water level is still off, you should call a plumber. A plumber can easily fix the issue.

• If you need to replace any parts, consider buying a universal toilet repair kit from a hardware store or supermarket. It includes a valve, float, and flush valve that fit most toilet models. This kit can help resolve water level issues, weak flushes, or constant water running problems.
• If you have difficulty disassembling the toilet components, it's best to call a professional plumber.

• Make sure not to overlook any small details when reassembling the toilet. Missing even one part can lead to water leaks or gradual damage over time.
• When installing the new water supply valve, ensure that the components are reassembled in the correct order.

• Screwdriver
• Bath towel
• Dishwashing sponge
• New water supply valve (optional)
• Wrench or pliers (optional)