How to adjust water level in dual flush toilet bowl

How to adjust water level in dual flush toilet bowl. The working of a dual flush toilet bowl differs from the single flush toilet bowl. It has two options for flushing.

1st is half, and it uses only half aqua in the tank. While the other is full and uses a full tank to wash.

It uses buttons rather than a flapper. The aqua level affects the working. Sometimes it is set wrong, so we need to adjust it. Mine wasn’t flushing properly.

So I surfed the internet and found a way to set it. But it wasn’t very explaining, so I wrote this article for people who want to understand easily.

How to adjust water level in dual flush toilet bowl

adjust water level in dual flush toilet bowl

Adjusting the level in a dual toilet bowl is actually very simple. No extra tools are required. We just need screwdrivers. It doesn’t even take time.

Draining comes first. The tank should be empty. The tank lid needs to be opened.

You need to adjust the float. The fill valve handles the running of water. You need to replace it to match the attachment. The toilet needs to be unclogged.

The vent stack should be unclogged too. Refilling the tank and setting everything up is important. Tightening the screws in both directions makes water flow better.

The process by step is listed below.

Turning the water supply off

Empty the tank. The hoes from the wall need to be closed. Key supply can be turned off with a valve too. Press the full wash button to drain the water completely.

Some water will remain in it. Don’t worry; it doesn’t have to be completely empty.

Opening the tank

After the water is off, lift the lid off the tank. It isn’t screwed or attached, so just lift it. Place it on a flat surface.

There are fill lines in it. They show the rising level of water. Adjusting them will affect the level as well. The power level is affected by change too.

Suppose the water is kept above the line. The flush will be more powerful. The opposite is also possible.

Setting the valve

setting the valve

It is a tube that extends to the cup and has an arm. It is for controlling the water level. Reach the notch at the back and turn it anticlockwise. This will free the valve. You can use a screwdriver to push it if it is hard to reach.

Now set the valve height low or high. Raising it will cause increasing while lowering it will decrease it.

Push the valve in the desired direction until you achieve the results. The arm we noticed earlier is a ball valve. It refills the tank.

There is a screw at the end, which you can move to set the level by using a screwdriver. Set it exactly at the same level as the fill valve. If the ball pops out, just put it back and set the level so it won’t fall again.

Raising the fill valve above the overflow valve will cause an overflow. It is the smallest tube between the valves in the tank. Level them by bringing them to the same point, so it doesn’t overflow. Press the clip and use a screwdriver to slide it.

Press the notch again for unlocking. Keep pulling until they are even. Pull the notch and clip it, so it’s closed. Test it out. Then set the lid and close it.

Level setting by clogging

The valve and float will set the level as they control it. But if the level is still not set and it is low. That means there is something else doing this.

If the toilet is partially clogged or its pipe is blocked. The level of water in the bowl will raise high. The water will slowly be siphoned out.

You need to unclog and unblock it to make the level equal. You can use vinegar, lemon, salt, baking soda, and borax to clear the blocking.

You can also use manual force through a plumber snake and a plunge to clear it out. Once the clogging is no more. The water will not siphon out of the hole.


Caused by clogging or wrong setting. There are problems like noise that can arise. The water may come out of the tank if the bowl level is set too high. Water may also come out if there is clogging or blockage in the pipes or the bowl.

Setting the level by valves or by unclogging will eradicate your problem. Follow the above steps to try both methods.

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