If you notice your toilet bowl losing water, it’s important to identify the source of the problem. Your toilet bowl water level might fluctuate due to several common problems.
One common issue is a blockage in the vent system. You might also experience water loss due to a cracked toilet bowl.
Causes of Low Water Level in My Toilet Bowl
You might be able to determine the cause of the water level without even needing a plumber. It’s important to diagnose the issue, since different problems are solved in different ways.
Toilet Bowl Crack
A crack can cause your toilet bowl water to leak. You’re more likely to experience this with an old model as opposed to a new toilet.
With this issue, you’ll notice that the water supply creates puddles on your bathroom floor.
However, there are some cases where the leak is located in the drain line. When water leaks from the waste pipes, it can cause flooding inside your walls.
You might not even notice that anything is amiss with your plumbing systems.
Clogged Vent
The other most common cause is a partial clog or full clog in your air vent. The air vent helps to balance pressure when the toilet flushes, allowing for the toilet fill.
This is part of what allows water flow while preventing sewer gases from escaping into your bathroom.
The vent opening is located on the roof. This means that the plumbing vent pipe will deal with obstructions and clogs over time.
Debris like leaves and nests can lead to a clog.
Identifying the Cause
First, you should check to see whether there is leaking around the base of the toilet. If not, then there are a few more steps to follow.
Check the Toilet Tank
Sometimes the tank water level isn’t as high as it should be. Lift the lid off the tank to check.
The water should come up to just under the overflow tube. If it is too low, you might need to adjust the fill valve.
Open Faucets
You’ll want to make sure that the supply line isn’t compromised. Open the water shutoff valve and the other faucets by turning them counterclockwise.
Listen for Gurgling
Do you hear gurgling as the siphon moves water down the drain? If that’s the case, then you have a problem with your air vent.
You have now diagnosed the main issue.
However, if you don’t hear gurgling, then you should complete the next steps.
Shut Off Faucets
Now you’re going to turn off the faucets and the water supply. That way, no more water will flow through the bathroom pipes.
Test Levels
Time to test the water levels. With the water supply shut off, no more water should enter the toilet tank.
You should mark the water level inside your toilet tank with a waterproof marker. Then wait for at least two hours and return.
If the water seems to have drained, then there must be a crack in your toilet bowl or in your drain pipe.
Fixing the Issue
Now that you’ve identified the problem, you can increase your water levels. Each cause has a different potential solution.
Replace Your Cracked Bowl
If the issue isn’t with your air vent, then you need to replace your cracked toilet bowl. Once you have your replacement, you can close the water supply line.
Make sure you have buckets, gloves, and dry towels on hand.
Flush the toilet so that the water empties from the tank. Open the tank and use the towels to soak up the remaining water.
Uninstall your toilet bowl by removing the supply hose, unscrewing the tank bolts, removing them, and disconnecting the bowl.
Then you can install your new toilet bowl according to the assembly instructions. If it’s a one-piece model, it will also include a tank with a new flange, fill tube, and flapper.
Clean Your Air Vent
It’s simpler to clean your air vent than to replace your entire toilet bowl. However, since the vent is on the roof, you must be sure to take extra safety precautions.
Bring your garden hose up to the roof. Have someone below turn on the faucet.
Then push the hose into the vent itself. It will clear out the debris.
If the water overflows and spills from the vent, that means you’re dealing with a clog. A bad enough clog will require a toilet auger.
You’ll drill the auger through the clog, break it up, and lift it out the same way you would if the clog was in the pipes.
Final Thoughts
When your toilet bowl is losing water, you can often fix it without needing a screwdriver or a plumber. If your toilet bowl is cracked, you’ll need to replace it.
And if the air vent on the roof is clogged, you’ll need to clean it.
It’s fairly easy to DIY solutions to these problems. But if you aren’t up for cleaning your vents or replacing your toilet, you might contact a plumber or handyman to handle it for you.