Water level drops in bowl after it fills

Water is not draining completely from the toilet line to the sewage tank. If there is a 'low/little slope' section anywhere in that drain line, solids WILL settle and collect there and cause water to back-up in the toilet drain line. Then the toilet will not flush completely or at all until the 'soft blockage' is cleared out and the drain line emptied. Al 'gravity drain' toilets require a free draining/empty drain line that allows flush water to drain unrestricted. A basement toilet has a pump that 'forces' flush water up and out with enough pressure to sometimes force out the 'soft clog.'

check to see if waster continues to run into the bowl after the plunger has returned to stop water flowing. If it is a slow leak then replace the flush washer on the stopper plunger.

2 possibilities.1. The water level is set higher the the overflow tube. This will cause the water to run into the overflow continuously. You should be able to see this. 2. The large seal - bottom center of the tank - is leaking. This will cause the water level to slowly drop after a fill. The water tank will start to run again after flushing - BUT NOT CONTINUOUSLY. You should see if there is a small amount of water flowing from the rim to the bowl 15 seconds after the water has stopped running after a flush.

Hi, if you remove the cistern lid and flush the toilet, look at the float (back left) to see if this is rising freely when the water fills back up. Once the water has stopped filling, check the fill level lines on the large syphon in the middle of cistern. Your model of toilet has an eco flush which will be lowest line to save water, so not as much water will flush out. There is a long plastic screw on the float (back left) which you can turn to adjust the water level to the higher line on syphon (1.6 gallon flush) and turn it slowley till the water level reaches that mark. flush a couple of times to see it is filling back up to the set amount.

Check to be sure small tube is flowing inside the ovefow tube. This is the water that flushes the rim holes, and refills the bowl. If you don't have flow clean or replace the float valve.

1- Check ports out under rim all round bowl.

2-Check tank fill level for required amount to with in 5/8" to top of over flow tube.

3-Make sure 1/4" fill tube is connected to over flow tube. From fill valve to overflow tube.

Below is a few details to go by I hope will be helpful for you to take care of this problem.


Under the rim of the bowl check the ports and make sure they are not stopped up. You can open them up with nail or pin to clean out ports.
Next check tank level and make sure the fill valve has a line run from it to top of the overflow tube. This line allows water to goe to bowl and tank to fill required amount needed.
Water in tank should be within 5/8" to top of over flow tube.

I don't exactly know what you mean so i will cover all the basics. The fill valve sends fills water in 2 locations. 1) the fill valve fills at the low end (from the bottom to the top) of the tank. This is the flush water level. It needs to be stopped by a float switch before the water overflows into the over flow tube.
2) the fill valve fills water via a small tube at the top of it which this tube NEEDS to be pointed into the overflow tube with a high arch. THIS water is filling your toilet bowl section to proper flushing height. If your water in your bowl does not reach proper height and someone removes this tube to aim it into the tank where the other water is stored, THEN you may have the problems you described and you will need to do several flushes to remove waste.
SO to reiterate 1) make sure your float cuts off and stops the filling cycle before the water flows into the over flow tube. This is done from 1 or 2 adjustment screws. and 2) make sure the small black tube is aimed down into the over flow tube with a good arch. The arch prevents back siphon.

Check the fill tube in your toilet one easy way to see if it's leaking is get food coloring and pour in your tank to color the water this makes it easier to see and squeeze the tube in the tank when it's full if you see the colored water running down the middle of it you have a winner! if not you can look around for it sometimes the plastic under the flapper gets cracked too

First off,If the air vent was clogged the toilet would back up and overflow and when it did flush, it would make a gurgling sound.
secondly the water level in the bowl is not important as long as it covers the opening,The water is only there to keep out sewer gases so they don't enter your home and the shape of the trap will always maintain the proper amount of water needed to prevent this.
The previous water level may have been due to a partial clog that has since been removed.

Replace your stopper at the bottom of the tank. While you do hat you should also just go ahead and replace the float. 25 dollars for everything and 10 minute worth of your time