There are several possible reasons for a slow flushing toilet and determining the cause is necessary before the problem can be fixed.
Common causes of a slow flushing toilet include clogging, a part failure and water issues.
To help solve your slow flushing toilet problem, let’s take a look at possible reason for your toilet issues and the possible fixes below.
How does a toilet work?
A toilet works due to simple gravity. Water will always flow downward because of gravity.
The toilet tank at the top is where water is kept. When you flush the toilet you open a plug (i.e., flapper valve) that allows water from the toilet tank to flow into your toilet bowl below.
The water travels further down from the toilet bowl to the toilet drain through an S trap, which is the bend under the drain beneath your toilet. Finally, it travels out through the main sewer line.
So to summarize, because of gravity, your flushed toilet water starts at the top (your toilet tank) and flows from the toilet bowl to the S trap and into your city’s sewer line, where it will eventually be treated.
Troubleshooting a slow draining toilet
There are many reasons for a slow flushing toilet (i.e., lack of flushing power). Generally, however, it is one of the following three causes:
- Clogging (most common)
- Part failures
- Water issues
Let’s take a closer look at each one.
A slow flushing toilet can be caused by clogging
A clog or blockage is usually the main reason for your slow flushing toilet. It is easy to identify and fix each of the clogs mentioned below.
A clogged S trap
Attached below to the left side of the toilet is a S-Shaped pipe called the S trap. Because it is a curved shape, waste and debris (i.e., paper) can easily be caught and become difficult to dislodge. If you don’t get rid of it, you will have a slow draining toilet.
How can I clear a blocked S trap?
A common plunger is all that’s needed most of the time.
Place the plunger on the drain at the bottom and pump it up and down quickly. The drain should now be unclogged.
One caution: If you plunge too hard, you could damage your pipes. You should not overdo it with the plunger.
Too much toilet paper or other debris placed in the toilet bowl
A clogged toilet is most often caused by using more toilet paper than your toilet system can handle. It happens all the time, particularly in older homes. You should always limit the amount of paper thrown into the toilet bowl.
Although toilet paper is meant to dissolve in water it can leave behind a sticky, gummy residue. There is some types of toilet paper that is thicker (i.e., 2 ply). This toilet paper may be more comfortable, but it can be more difficult to flush through your system.
This can be especially true for sewer line piping that has issues (i.e., cracks or rusted/corroded interior surfaces that will catch debris passing by).
How can I get rid of too much toilet paper?
Your handy dandy plunger can come in handy again, just as with the S trap fix. Simply place the plunger on the drain and pump it until the drain opens.
Repeat this several times until you are satisfied with the solution. You can test by flushing the toilet again.
If that fails, call a professional plumber. If you have a toilet paper clog or something similar, they will be able to diagnose and fix it using a drain snake.
Part failures that cause slow flushing toilets
Broken fill valve
The fill valve does exactly what it sounds like. It refills the tank after a flush. You’ll usually notice you have a problem if your water is keeps running after the tank has been flushed.
This is more than annoying. A broken valve can cost you money due to water waste.
How do you replace a broken valve?
This will require a little bit of a toilet repair. First, turn off the water supply to your toilet. Then, open the tank, and flush the water out.
Now, disconnect the water supply hose from fill valve. This is done by unscrewing the nut that connects them.
Take the valve off its base and replace it with a new fill valve.
Reconnect the water hose to the fill valve and turn back on your water supply.
Blocked jet holes
Flushing causes fast moving streams of water to flow into your toilet bowl. These water streams come from tiny holes (i.e., siphon jets) located under the toilet rim.
If the jet holes aren’t cleaned regularly and thoroughly, they can clog up due to mineral buildup (caused often by hard water use) or bacteria. You’ll have a slow flushing toilet in either case if you don’t have clean jet holes.
How can I fix blocked jet holes?
Use a small mirror in order to see the jets under the toilet rim. Bacterial grown will look like black or dark orange spots. Mineral deposits will look like grey scales.
In order to prevent bacterial growth, first prepare a bleach solution (10 parts water 1 part bleach)
Pour the bleach solution into the overflow tube and let it sit for about ten minutes before trying to flush again.
Use a mirror and a piece wire to unclog the holes. Next, use a toilet cleaner and toilet brush to clean the underside of the toilet rim. Repeat until there are no more dirty jet holes.
The process is slightly different for mineral deposits. Instead of bleach, use vinegar. Heat up twelve ounces of vinegar to 120 degrees and then pour into the tube. Wait around an hour before flushing. Use your wire and mirror to scrub each jet. Repeat the process as necessary.
Old toilet
You might have an old porcelain toilet that has worn parts and seals. Older toilets are prone to maintenance issue.
How can I fix an old flushing slowly toilet?
It is best to purchase a new modern and high efficiency toilet. A new modern toilet will cost you between $100 and $400. You can find both round and oval form models.
Water issues that cause slow flushing toilets
Too little water
This is a simple problem to identify. The water level should be around 1/2 inch below the top edge of the overflow tube. If the water level is below the top of the tube, it means that there isn’t enough water to flush the tank.
How can I make my toilet flush faster by adding more water?
Fill a bucket with water, and then pour it into the tank. The overflow tube can be described as a vertical tube that has an opening at its top. It also has a rubber pipe that runs into it. After you have filled the toilet tank with enough water, run a few test flushes. This should resolve the problem.
Hard water
Hard water will contain dissolved mineral such as calcium or magnesium. It is easy to see hard water after you wash your dishes. It is the soap scum that has accumulated on your glassware. These minerals can accumulate inside your pipes and cause water to flow more slowly.
How can I get rid of hard water buildup in my toilet tank?
The cleaning is very similar to the way you clean your toilet’s jet holes, but there are some key differences. First, you will need one quart of distilled white vinegar. Pour the vinegar into the toilet tank overflow tube. Leave overnight in order to allow the calcified minerals to dissolve.
In the morning, flush the toilet a few times to check if that the solution worked. If it did not, you may need to have a professional plumber come out remove the buildup. You might also need to install a water softener. A water softener prevents the buildup of minerals inside pipes, hot water heaters and other home fixtures.
Final thoughts
There are many reasons why you might have a slow flushing toilet. Hopefully, the ideas above can help you quickly restore the flushing power to your toilet bowl and rid your home of a slow flushing toilet forever.
