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How To Make A Toilet Flush Better. Say Goodbye To That Second Flush

What Causes Weak Flushing In A Toilet?

A problem that almost everyone has run into is going to flush the toilet and the toilet you are using has too weak of a flush to get the job done the first time.

This leads to awkwardly having to wait until the flush has refilled and hoping that it will work the second time.

This can be a problem in your house, or in someone else, or even in public restrooms, but it is a problem that seems to always come back.

This may just seem like a problem you have to cope with, and you will have to spend a good portion of your life waiting for your toilet’s flush to be able to work, but this is not the case, and like most plumbing issues, does have a solution!

If you are suffering with a toilet in your own home that has a weak or slow flush, this is nearly always a signifier that you have a clogged toilet drain, or it is at least partially clogged.

It could also be an indication that your toilet’s rim jets are blocked, that the water level you have in your toilet’s tank is dwindling, or that the flapper in the toilet is not fully opening or maybe that  your vent stack is either clogged or partially clogged. 

A quick fix to make your toilet have an improved flush is to try to adjust the water level within its tank, do this so that the level is around half an inch under the overflow tube.

After his give the rim holes a clean as well as your siphon jet. Then check to make sure that there’s no clog in your toilet.

You may also want to change the chain length of your flapper and maybe clear the vent stack if you notice it is unclean. 

A toilet’s design leans towards a powerful flush, it is unlikely that a toilet is designed to have a weak flush.

Toilets accomplish this by having enough water stored inside the tank to be able to dispense it into the toilet bowl fast enough to dispose of the waste.

This means that when there is a weak flushing toilet (see also ‘Can You Flush Hair Down The Toilet?‘) it is because of something stopping this happening and inhibiting the flow.

So let’s look at how to fix all the different factors that could be causing this.

How To Make Your Toilet’s Flush More Powerful?

The ease at which you can fix your toilet to make it flush better depends on which factors inhibiting the water flow you will have to fix and how many of these factors are a problem.

Depending on how well-designed your toilet is, some of these components will be easy to fix, but it not you may even need to contact a professional.

Let’s go through the most common ways to fix this issue!

Unclogging Your Toilet

When it comes to a clogged toilet (see also ‘What Liquids Can You Use To Unclog A Toilet? Is Drano Ok?‘), two main different types of clogs need to be taken into account. Firstly, the toilet is completely clogged, and the water will not flush out at all when you want it to.

How To Make A Toilet Flush Better. Say Goodbye To That Second Flush (1)

And secondly, when the water is able to drain when flushing, but it is partially clogged and the flow is inhibited creating a weak flush that is usually ineffective.

This will make it, so the water will rise as well as drain slowly which can occasionally cause overflowing water which is never pleasant.

To check that this is what you are dealing with you can do a bucket test. This is done by filling a bucket and then putting all the water in the toilet bowl quickly.

If the toilet is not able to flush this water effectively you can tell that a clog is your problem.

This test is effective as it isolates the cause and lets you know it is not any other problem causing a weak flush.

So the best way to solve this problem is by either plunging or snaking your toilet.

The best type of plunger for toilets is using a plunger in a bell shape as they have the best shape for solving this problem.

After you have plunged or snaked the toilet hopefully the problem has been solved  can test this with the bucket test again which hopefully it will pass this time.

If it does not, you may need to buy or rent a toilet auger.

Adjusting The Water Level In Your Toilet Tank

You can either have a toilet that has a slower flow or you can have a toilet which can flush up to 3 and a half gallons every time you flush, but no matter how much your toilet can flush, the tank of the toilet will need to have a precise volume of water to be able to act as good as it can.

If your water level is underneath this amount, you will get a weak flush no matter what.

This is why adjusting the water level in your toilet can improve the strength of the flush.

As previously mentioned, you ideally want the water level in your tank to be around a half to an inch underneath the overflow tube.

You can recognize this overflow tube as being the biggest tube usually located in the central area of the tank.

This tube works to send excess water within the tank into the toilet bowl to make sure that the tank is not overflowing. 

If this is the problem you are facing with your flush, you are in luck as the process of fixing it is simple and easy only needing a screwdriver.

  • First remove the lid to your toilet tank and leave it somewhere where it is not in danger of breaking.
  • Now look at the water level and compare it to the distance it is from the overflow tube.
  • If you see it is over an inch from the overflow tube you will need to make it rise.
  • Look to see if you have a float cup or float ball in your toilet.
  • If you have a toilet that has a float cup, keep an eye out for a longer plastic screw that should be near the float. Found it? Great; turn it counterclockwise using your screwdriver until you see the water rising to less than 1 inch from your overflow tube
  • If you use a float ball, you should find an arm connecting the ball to your fill valve. On the connector to this valve you should find a screw which using your screwdriver you should adjust counterclockwise to get the water to an appropriate distance from the overflow tube.

Once you have completed this process, hopefully your flush will be significantly more powerful than it was before!

Adjusting The Flapper Chain In Your Toilet

Most toilets have a toilet flapper that acts as a rubber seal which sits on your flush valve as well as on the lower portion of the tank of your toilet.

This flapper is ideally connected to your handle arm of your toilet usually by a smaller chain.

If you depress the handle of your toilet down as it flushes, the chain that should usually be slack will gain tension that will lead to the flapper lifting off of the flush valve making it open.

If you are wanting your toilet to have a powerful flush the flapper will have to lift vertically allowing the water to go from the tank into the bowl fast enough for a good flush.

However, if your lift chain is too slack, the flapper may only partially lift which will make the water take too long to go from the tank into the bowl resulting in a weaker flush.

The correct amount of slack for a lift chain to have is about half an inch.

To fix this issue you will need to unhook this lift chain off of the attached toilet handle (see also ‘How To Fix A Loose/Wiggling Toilet Handle Fast!‘), so you can adjust the length which may take a few attempts to perfect.

Make sure that you do not do this too tightly however as then the flapper chain will constantly leave the valve open making your toilet constantly flush which is its own issue.

Cleaning Your Toilet Siphon And The Rim Jets

As you are flushing your toilet, the water will be entering the bowl from a part of the toilet called the siphon jet located in the lower portion of the toilet bowl while also running through jets around the rim aptly named rim jets.

How To Make A Toilet Flush Better. Say Goodbye To That Second Flush (2)

If you have an older toilet that has had a lot of use, especially if you are in an area with low water quality or hard water, your siphon and rim jets will inevitably get clogged, usually by mineral deposits like Calcium.

This will of course limit the flow of water out of the tank which we now know will drastically impact the power of your flush.

Cleaning these parts of the toilet should get your toilet working well again, this is done by:

  • First turn off the mains supply of water by shutting the valve on the wall usually behind the toilet. This is usually achieved by turning it clockwise but also using a push or pull valve if you have one.
  • Then flush your toilet and keep it flushing as long as possible.
  • After this remove the tank lid safely
  • Then using a sponge to soak up as much excess water from the lower part of the bowl as possible, this is when you realize the importance of wearing gloves.
  • Cover your toilet rim holes using duct tape and place a funnel within the overflow tube,
  • Gradually pour in around a gallon of any vinegar (if you warm it first it works more effectively)
  • If you don’t have access to this much vinegar a 1:10 mix of bleach and water works well
  • After leaving for an hour remove the duct tape and use a 3/16 inch Allen wrench in an L shape to fully get rid of any excess build up from each hole.
  • After flushing all the build up should be gone.

Unclogging Your Toilet Vent

If none of the other methods have worked then it is likely the vent stack which connects the vent stack that removes air from drainpipes may be inhibiting the flush by removing too much air from the system.

This vent will not be too hard to fix but be careful accessing it on the roof. Pouring water from a hose will help clear clogs and hopefully solve the issue.

If this does not work using a toilet cleaning snake may also work.


So now you know all the main problems that cause a weak flushing toilet and the best and easiest ways to fix them all.

Which one did you end up needing to fix, and how easy did you find fixing it?

author avatar
Anthony Barnes
Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age


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