1. Your toilet’s fill tube is damaged.
If you’re experiencing a poor or sluggish flush, it could be that your toilet’s fill tube is kinked, damaged, or broken. A fill tube is a plastic hose connecting the water control and overflow tube, refiling your toilet bowl each time you flush.
How to fix: If it accidentally became unattached, re-attach it to the overflow pipe using the S-clip. If it's damaged, you’ll have to replace it. You can do it yourself or get a local professional to do it.
2. Your toilet has a clogged sewer vent line.
If your toilet is making loud gurgling sounds, blows out bubbles when you flush, or gives a weak flush, you could have a clogged sewer vent line. For a proper flow to happen, the vent must be open. If the vent pipe is blocked, the water flow creates a vacuum, slowing down the flow of waste. This could also clog your sewer line as it flushes waste out of your toilet.
How to fix: You can try removing whatever is obstructing the sewer vent pipe. Take a garden hose to the roof and run water down the vent pipe. This will force the obstruction down the sewer pipe, clearing the vent.
However, you may want to get a professional to do this instead. Going up to the roof always involves a risk of you falling and hurting yourself.
3. Your toilet may have worn-out parts.
Most toilets have four main components that allow them to work. These parts may need fixing or replacement if water levels are low.
How to fix:
- The toilet flapper. Pour some food coloring into the toilet tank water and check if the water in the toilet bowl changes color. If yes, you need to change your flapper.
- The flush valve. Fill the tank, then turn off the water supply at the shutoff valve. Mark the water level and let it sit overnight. If it drops to the bottom of the flush valve, you may need to change the flush valve.
- The fill valve. Check to see if water is going over the top of the overflow tube on the flush valve. If it hisses or drips continually, some debris may be stuck inside. Clean the valve to see if it works properly again.
- The trip lever. If you experience erratic flushing, the trip lever could be wearing out. You'll need to change it.
While you can replace all these parts yourself, you can also hire a professional to help.
4. Your toilet could have a partial clog.
If you have low toilet water levels, you could have a partial clog slowly siphoning water from your bowl.
How to fix: Use an auger with a bulb head to clear the clog. Check out this guide on how to unclog a toilet with or without a plunger. You may also want to read our guide on how to use a plumbing snake.
5. Your toilet could have insufficient water inside the tank.
Sometimes, the water level in a toilet bowl is low due to insufficient water inside your toilet tank.
Open the tank cover and check the level of water once the fill valve has shut off. It should be about an inch below the overflow tube’s opening. If it is lower than that, you may not have enough water to fill the bowl after you flush.
How to fix: You can correct this by adjusting the fill valve float.
6. Your toilet could have a crack.
You may be experiencing low toilet water levels because of a hairline crack in the bowl. Remove the toilet to look at the subfloor. If there is water, there's a crack in the bowl.
How to fix: You have no choice but to replace the toilet bowl. Talk to a plumber or a professional who specializes in plumber repair to get price quotes for a replacement.
How do you raise the water level in a toilet bowl?
If your toilet has a ball-and-arm float, you’ll need to turn a screw on the float valve clockwise to raise the water level. You may also bend the float arm to adjust the water level to how you want it.
If you have a cylinder float, you’ll need to press or squeeze the release to move the cylinder to where you want it. You may also have to rotate the adjustment dial instead.
Read more on how to raise the water level in your toilet.
Hire a plumber to fix your toilet problems.
While low water in a toilet bowl is nothing to be alarmed about, it can be annoying — especially if you can’t pinpoint the problem.
Quit stressing and hire a pro to troubleshoot your toilet issues. Download the Thumbtack app today to see a list of top-rated local plumbers. Get free cost estimates from a few of them, and schedule an appointment before they're all booked up.
FAQs.
How much water should be in the toilet bowl after flushing?
Toilet bowls are designed to hold a specific amount of water for optimum efficiency and flush. Water levels in your toilet bowl are determined by the piglet height of its internal P-trap. This may vary from one toilet bowl to another.
Consult your owner's manual for more information.
Can I add water to my toilet tank?
Yes, you can add water to your toilet tank. Simply adjust the ball-and-arm float or cylinder float to accommodate more water.
For a more detailed guide, read this article on raising the water level in the toilet tank.
How do I know if my toilet is losing water?
You need to look at and listen to your toilet. See if a large leak causes moving water in your bowl even after your toilet tank has already been refilled. You can also try the food coloring test to see if water flows out from the tank even if you’re not flushing.
Also, pay attention to how the toilet sounds after you flush the toilet. It should only make a refill noise when the tank refills after the flush. If it makes any noise at any other time, you may have a leak or a problem with some parts of your toilet.
