If you notice that the water level in your toilet bowl is too low or too high, there are ways that you can adjust it. But first you should know that these are usually signs of some trouble that is starting to brew.

Reasons Why Your Toilet Bowl Water Level Is Low

  • A problem with the Fill Tube – inside your toilet tank you will find a small, plastic tube that is connected to a larger tube (the Overflow Tube). The smaller tube is called a Fill Tube and if it’s damaged or has somehow disconnected from the Overflow Tube, then you will see lower than normal water level in your toilet bowl.
  • A crack in your toilet bowl – it doesn’t happen often but your toilet bowl could have developed a crack and this loss of water would cause the water level to be lower. Normally, you would notice water on the floor by your toilet if this occurs. To confirm that the water is coming from a crack in the bowl, run your hand along the entire outer side of the bowl to feel for any leaking water.
  • There’s a block in the sewer vent line – any blockage in the sewer vent line could also be the cause of lower water levels in your toilet bowl. The cause of the clog could be anything ranging from leaves to birds.
  • A problem with the Fill Valve – When you flush your toilet, water goes into the Fill Valve from the bottom and travels through the Fill Tube and the tank then gradually begins to fill up with water and raises a float attached to the Fill Valve. Once the float reaches the top, it pushes down on a diaphragm inside the Fill Valve which stops the water. The tank is now refilled with water.
  • A problem with the tank’s float – The plastic ball that is attached to a long arm on top of the Fill Valve is the Float. If the float or the arm are damaged somehow the water level in the tank (and the bowl) will be affected.

Reasons Why Your Toilet Bowl Water Level Is High

Oftentimes, the main reason that the water level in your toilet bowl would be higher than normal is due to some sort of blockage in the sewer line. Of course, as mentioned above this blockage could also be the cause of low water levels in your toilet bowl.

Other signs that you’ve got a clog in your sewer line are…

  • Gurgling sounds from your drains or toilets.
  • Water backing up out of drains or toilets.
  • Water pooling around drains or toilets.
  • Smell of raw sewage coming from your drains.

Several Ways To Adjust The Water Level In A Standard Toilet Bowl

  • If the problem is the Fill Tube – it will either need to be replaced (if it’s cracked or damaged). But if it has simply disconnected from the Overflow Tube you can just re-connect it. Of course, if it keeps disconnecting then the Fill Tube should be replaced.
  • If the problem is the Fill Valve – it will most likely need to be replaced.
  • If the problem is a cracked toilet – we highly recommend that it be replaced with a new toilet.
  • If the problem is a blockage in the sewer vent line – we recommend that you call in a professional plumber to assess and eliminate the clog.
  • If the problem is due to the Float in the tank (or it’s arm) – it’s best to replace them.

Of course – there are instances when the other factors may be causing problems with your toilet bowl’s water level. Call in a professional plumber to get a complete assessment and repair.


If you have any questions about problems with your toilets, call Atlantis Plumbing today at 770-505-8570. We are available 24 hours a day, 7 days a week.