4 Reasons Why Your Toilet Doesn’t Flush All the Way & How to Fix It

Written by

Paulk Webb


Freddie J. Hagopian

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reasons why your toilet doesn't flush all the way

Are you tired of dealing with a slow toilet that won’t flush completely? It’s a frustrating and embarrassing problem that many homeowners face. There could be several reasons for such an ordeal and understanding the root cause is necessary to find the right solution.

From a clogged drain pipe to a faulty flushing handle or button, there are many common reasons why your toilet might not be functioning as it should.

Below, we’ll explore the common reasons why your toilet doesn’t flush all the way with some tips for addressing the problem.

List of Reasons and How to Fix a Weak Flushing Toilet

When your toilet water won’t go down, it might be because of the following issues:

</p> <h3>Reason 1: Toilet clog</h3> <p>


One of the reasons why your toilet won’t flush completely is that it might get partially or wholly clogged somewhere down the toilet’s pipe.

Inside the toilet base, a curved part should stop the sewer from escaping the drain pipe by containing a small amount of water. This curved shape is ideal for dirt and non-degradable items to get stuck.

These culprits can be toilet paper, cotton pads, and hair, which hinder the water flow and cause the toilet to flush more slowly than normal. Even worse, the toilet flushes but poop stays. Yuck!

  • How to fix it?

Using a toilet plunger or an augur is often necessary to correct flush toilet problems.

Try to plunge several times to remove the materials that could be causing the clog, then flush the toilet to check whether the problem has been resolved.

If you decide to use a toilet auger, or a toilet drain snake, follow the guidelines and instructions carefully.

Lastly, by throwing a small piece of paper in, you can measure the power of the water flow by checking whether your toilet leaves paper after flush.

While most clogs can be cleared with a plunger or toilet auger, persistent clogs may indicate a more serious problem that calls for professional plumbing help.

If your toilet still flushes weakly but not clogged at all, it can be because of the following other reasons.

</p> <h3>Reason 2: Faulty handle and chain</h3> <p>


There may be some issues with the toilet handle and chain, which is the second factor that could account for the low water pressure in toilet.

Water may not flush as expected if the inner system in the toilet tank is malfunctioning due to a loose handle or an unclipped, improperly positioned chain.

  • Flapper

A partially opened flapper, which restricts the amount of water that can flow down the toilet, could be caused by a loosening handle and chain.

  • Chain

A broken chain may not be able to raise the flapper, which would prevent any water from draining at all; hence, when you press the handle, the toilet flushes but water doesn’t go down.

  • How to fix it?

To fix a faulty chain and toilet handle that causes your toilet not flushing strong, you can start by checking if the chain has the perfect length or not.

If the chain is too long or too short, adjust it by removing the chain and re-hooking it farther or closer to the flush handle. About ½ inch of slack is enough for the chain to function properly.

If the toilet still does not flush all the way unless you hold the handle, the problem might lie in the flapper.

It might be warped or cracked due to old age; consider replacing it or calling a plumber and letting them help you with this issue. A broken flapper may cause water to leak into the bowl, and there might not be much water left for a powerful flush.

</p> <h3>Reason 3: Problems with rim jets, siphon jets (inlet holes)</h3> <p>


Under the toilet bowl’s rim, there are rim jets and a siphon jet, or the inlet holes, where water from the toilet tank flows through them.

Mineral buildup, debris, or bacteria could get clogged inside these jets and hinder the water on its way to the toilet drain hole. As a result, your toilet flushing slow and weak could occur since water pressure is reduced because of those blockages.

You can observe the signs of clogged inlet holes by looking at the speed and the water flow of the draining process. The water might flow slowly and go straight down the toilet hole instead of flowing in a swirling motion like usual.

  • How to fix it?

Cleaning the rim jets and siphon jets is the best solution when the toilet not flushing all the way.

You may use a toilet brush or a scrubber to clean the jets directly; another option is to use a toothpick to remove debris and mineral buildup, preventing them from clogging the jets.

One useful tip you might want to know is that you can use a mirror to have a better view.

Also, if cleaning does not help, try using vinegar! You can pour 10 to 15 ounces into the overflow tube and let it sit for one or a few hours. Lastly, you can clean the toilet hole and check if it runs normally.

</p> <h3>Reason 4: The fill valve does not work properly</h3> <p>


A toilet weak flush could be caused by a float of the fill valve that is set way too low. As its job is to fill the tank with water after flushing, the fill valve controls the amount of water flowing into your toilet every time we flush with a float ball or a float cup around the toilet fill valve.

As the water reaches the right level of the tank, this float will close the fill valve and stop the water flow.

That is to say, if this float is set too low or is stuck, your toilet doesn’t flush completely due to the insufficient water needed for each flush.

  • How to fix it?

When a toilet is not flushing properly due to the fill valve having some issues with the float, try to adjust the float and ensure that the water level is set at the refill line.

You can bend the arm of the float ball upward a little until it is aligned with the right level. If your toilet has a float cup instead, there is probably an adjustment screw on the fill valve. You can just turn this screw clockwise, and the float will go up.

If your toilet flushes slowly and incompletely even after you fix the float, consider calling a plumber for help.


We know that when your toilet doesn’t flush, just fills with water, it is annoying since the toilet bowl can’t get cleaned properly. Rather than trying to live with the inconvenience, calling in a professional plumber to identify and remedy the issue will save time, money, and unnecessary frustration in the long run.

Knowing the reasons why your toilet doesn’t flush all the way is the first step you can take. And by taking action and finding a solution, you’ll be able to get back to a fully-functional toilet in no time!

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