How to Convert Low-Flow Toilet to High-Flow

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Isn’t it frustrating when you need to flush your toilet several times to clear whatever is in it?

Perhaps I’m making a big deal out of it, but it was important to me to convert my low-flow toilet to a high-flow one. It’s a matter of convenience and practicality because, hey, I use a toilet several times a day. 

It didn’t just improve the functionality of my bathroom — it also helped me save time and worry.  

And the solution turned out to be simple: increase the flushing potential of the toilet by placing the toilet tank float slightly higher.

So, if you’re dealing with a low-flow toilet, I’ll show you nine ways to improve its performance and increase the flush power.

Technically, you cannot convert a low-flow toilet to a high-flow toilet. What you can do is increase the flushing power of the toilet and make it more efficient. 

9 Ways to Increase Toilet Flush Power

Professional plumbers, homeowners, and manufacturers’ instruction manuals all have their ways of dealing with the situation. Here’s a list of all tips and tricks:

1 – Place the Toilet Tank Float a Little Higher

One of the first tips you’ll hear is to place the toilet tank float a little higher. The float prevents the tank from overfilling, so placing it slightly higher will allow for a few more gallons to enter the bowl — thus increasing the power of the toilet flush.

To start, remove the tank lid and find the screw connecting the tank float with the fill valve. Then, turn it counterclockwise to be able to move the float. From there, you can lift the float an inch or so to elevate the water level in the tank. 

The float adjustment screw keeps the float in a steady position at a certain angle. When you unscrew it, you can adjust the angle by lifting the float. The higher you go, the more water fills the tank.

This should allow about two extra gallons of water to go into the bowl when you press the flush valve.

2 – Make Sure There Are No Leaks

Sometimes, low-pressure toilets underperform because water is running out of them. If your toilet is leaking, you’ll need to fix it immediately. The way you approach this issue depends on what is causing the leakage, so you’ll have to inspect the entire toilet carefully. 

Check the toilet tank, hoses, valves, pipes, and other elements for leaks. If you find any, replace the faulty parts — this will solve the leaking problem and enable stronger toilet flushes.

3 – Reposition the Cylinder Float

The cylinder float is what raises or lowers the water level in the toilet tank. If it’s not positioned correctly, it will result in a low-pressure toilet. When the toilet is not flushing strongly, it means that the small stem on the tube is set lower than it’s supposed to be.

Adjusting the cylinder should be easy — turn off the water supply, empty the tank, and change the float’s position.

There is a small stem on the cylinder that you can grab to move the float. It should be about six inches below the top of the tank. Once you’re done, turn on the water supply and you’re good to go.

4 – Take Care of the Rim Jets

It is necessary to clean the toilet siphon and rim jets to ensure that water flows smoothly. If there are any clogs, mold, or other things built-up in there, remove them using a piece of wire or a brush. 

We like this tube brush — it’s both firm and flexible enough to clear any clogs in the rim jets. After that, water can run directly to the toilet bowl.

5 – Unclog the Toilet

Sometimes, even clogs in the drains can lead to low-flow toilets. In this case, you’ll need a plunger and a drain snake to fix the problem.

First, fill a bucket with water and pour some into the toilet bowl. Then, place the plunger inside — creating a tight seal around the drain — and push it rapidly up and down. This should create enough suction to displace the clog.

Remove any loose debris in the toilet bowl with a small fishing net before plunging into action again. A few tries later, and you should fully unclog the toilet.

6 – Change the Fill Valve

Another way to convert a low-flow into a high-flow toilet is to replace the fill valve. If it’s loose, the tank won’t be filling and only generates weak and mild flushing — if any.

I recommend changing the old fill valve out with a Fluidmaster valve. It’s powerful and has a straightforward installation manual.

The same logic of replacing necessary parts applies to the flush valve. 

7 – Use Bleach to Clear Clogs and Debris

Some homeowners remove clogs with bleach. To do this, drain any standing water inside the toilet and pour a bucket of bleach into the bowl from the rim jets. Then, fill it with no more than one gallon of water and flush.

This method will help eliminate the foul smell as well as clean the inside of your toilet bowl.

8 – Try With Vinegar and Baking Soda

This method relies on this acidic toilet bowl cleaner to displace calcium deposits from your toilet. Pour about an inch of vinegar into the bowl and add a cup of baking soda. Let it do its magic for an hour or two, then flush.

This will help soften calcium and can even prevent future clogs. However, do not expect it to clean the sturdiest grease and calcium deposits.

9 – Install a New Toilet

This is the last resort option, and I do not recommend it as it’s costly. However, if need be, you can always try and find a new, high-pressure toilet.

The Differences Between Low-Flow and High-Flow Toilets

How do you know that you have a low-pressure toilet? And what makes it different from toilets with a more powerful flush?

To put it simply, you’ll recognize a low-flow toilet based on the waste left in the bowl after flushing. If your porcelain throne can’t get rid of what’s in it, you have a low-flow toilet.

Two features stand out.

Water Consumption and GPF

The obvious answer is water consumption and the gallons per flush (GPF) ratio. It is the main distinction that reveals the flushing potential between low and high-flow toilets. The logic is clear — if your toilet consumes a lot of water, it’s a high-flow model.

Low-flow toilets only reach 1.6 GPF or less. On the other hand, a high-flow toilet is more efficient but consumes up to 3.2 GPF — and older models can go up all the way to 5 or even 6 GPF.

It’s a huge difference, and you can see it every time you flush your toilet. 

The main reason why modern toilets — tankless ones in particular — need less water is a stronger flushing pressure. It also has to do with environmental reasons, and we’ll go into more depth about that in the following sections.

Toilet Structure

The flush valve on a low-pressure toilet is usually wider than that of a high-flow toilet. The bigger valve makes it possible to wash away waste more efficiently since water can flow much quicker through it.

Besides that, the outlet on a low flow toilet is closer to the bottom of the toilet bowl. Manufacturers do this because gravity helps to propel most of the water out of the bowl — when you flush, the weight of the water is enough to pull it down.

Think Twice Before Increasing Toilet Flush Power

There are a few downsides to high-flow toilets, so you might want to take that into consideration.

The first is all about higher water consumption. It’s not good for the environment, which is the main reason for making low-flow toilets. However, the truth is that users often flush modern low-flow toilets twice, while high-flow toilets more often than not do the job in one try.

The second disadvantage of high-flow toilets is the cost of wasting more water in your toilet. It’s not vastly significant, but it’s possible you’ll feel the difference.

The Bottom Line

Most manufacturers make low-flow toilets by default, but you can take advantage of our tips to increase the water pressure.

Placing the toilet tank float a bit higher does the work for most toilets, but you can also reposition the cylinder flat and clean the rim jets. 

Besides that, you can make sure there are no clogs or leaks anywhere in the tank, change the flush valve, or use bleach and vinegar to clear any clogs and debris.

It’s simple and quick for you to increase the flushing pressure of your low-flow toilet, so roll up your sleeves!


Can you convert a low-flow toilet to high flow?

Technically, you can’t. However, what you can do is increase the flushing power of the toilet and make it more efficient.

Can I convert my toilet to a more powerful flush system?

Yes, you can convert it to increase water flow. However, the installation is not too easy for a DIY homeowner, so you might consider asking a plumber for assistance.

Do low-flow toilets clog more easily?

Low-flow toilets tend to clog more frequently because they use less water — the flushing power sometimes isn’t high enough to effectively remove waste. 

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