5 Reliable Toilet Flush Valves – Reviews And Buying Guide

Last updatedLast updated: July 23, 2021
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Let’s face it, the bathroom is one of the most important places in every home, which means every component in your bathroom has to be of the highest quality, including the toilet flush valve. Being the component that holds and discharges water when you flush your toilet, coupled with its ability to lower the amount of water you use and help fill your tank quicker, the best toilet flush valve is a must-buy for every homeowner. From minimal noise, an efficient flush system to economical water use, the probable benefits of a high-quality toilet flush valve are pretty numerous.

Due to the surplus of options on the market, however, buying the right toilet flush valve might not be as straightforward as it probably sounds. Does it leak water? Does it create noise? Or is it even water economical? All these are some of the numerous questions you must ask when perusing the several options on the market. To help simplify your work and save you from the tedious task of sorting through dozens of options, we have raked the web to bring you a list of the top five toilet flush valves on the market. The factors that aided our selection include size, weight, material, and warranty.

Containing a well-crafted comparison table, comprehensive reviews of five toilet flush valves, an all-inclusive buying guide, and a FAQ section in which several tangles are untangled, this article is an all-encompassing piece in which tens of hours have been judiciously invested. Not only has it been created to enlighten and educate you, but it has also been designed to duly convince you and help you determine which one will suit your needs best.

Top 5 Toilet Flush Valves Review 2021


KOHLER GP1083167Editor’s Choice

  • Size: 12.5 x 3.5 x 3’’
  • Material: plastic
  • Weight: 9 oz
  • Warranty: 1-year limited

More features: silent fill, fill-rate inserts, adjustable height

Not many names in the business of manufacturing plumbing products are stronger and more reputable than Kohler. Due to its high-quality and durability, the KOHLER GP1083167 is one of the most popular flush valves out there. Basically, it is an adjustable flush valve that is compatible with different KOHLER toilets. Apart from the fact that the size of the toilet fill is suitable for the majority of KOHLER toilets, it can also be obtained in several colors.

What’s more, the flush valve is mostly produced using high-quality and heavy-duty plastic, which won’t corrode over time. Besides, every necessary clip and washer locknut come in the package, which means you don’t have to shell extra cash on other items during installation. However, the installation of this flush valve might not be straightforward enough as the manuals contain unclear instructions. Although, you can easily solve this problem by hiring a professional plumber for the installation.

The package of this unit also includes many components that will help it fit several toilet tanks from Kohler and Fluidmaster. Moreover, the water inlet hole of this unit is extremely low, which aids its water economy. Also, it comes with various flow restrictors to enable it to meet the various flow requirements of nearly every toilet tank.

Why are we impressed?

  • Adjustable height
  • Fill valve is adjustable
  • Comes in many colors
  • Durable construction
  • Water economical

What negatives must you be aware of?

  • Unclear instructions

TOTO Combo KitBest Flush Valve Kit

  • Size: 12 x 4 x 2’’
  • Material: plastic
  • Weight: 6 oz
  • Warranty: 1-year limited

More features: fill valve and flapper included, self-generating hydropower, adjustable flow rate

If you’re already using a TOTO toilet in your bathroom, then the TOTO Combo Kit is the ideal flush valve for you. this valve is actually engineered with TOTO Flush tank in mind, so it’s not really compatible with other brands. However, while you can try it with other brands, just know that might not really perform up to your expectations. Among a host of features you will find on this flush valve include EcoPower and Hydrotect which allow it to self-generate hydropower and naturally reduce the pollution.

Furthermore, this flush valve has an adjustable height, which allows you to adjust its height according to your particular flush tank. The water flow rate of the unit is also adjustable, which is especially useful if you have a two-piece toilet installed. And installation-wise, this product is very easy to install. It comes with a detailed instruction manual and provided you properly and carefully adhere to every step, replacing the old valve won’t be difficult for you.

If you’re in search of a high-quality flush valve, this model is one of the ones you should be looking at. Although it’s pretty expensive, that shouldn’t be a deterrent for you to purchase it if you’re really looking for quality. However, this model is best used with a TOTO toilet tank, which is a drawback considering that most other top-of-the-line models are compatible with different flush tanks from different brands. Also, some parts of the plastic seem flimsy, which is another downside.

What makes it special?

  • The flow rate is adjustable for two-piece toilets
  • Self-generating Hydropower
  • Adjustable height
  • Easy to install

What cons did we find?

  • Only ideal for TOTO tanks
  • Expensive price

Sloan C-100500-K Flush CartridgeEasiest to Install Option

  • Size: 17 x 3 x 2’’
  • Material: plastic
  • Weight: 6 oz
  • Warranty: 3-year limited

More features: fits Flushmate tank systems

Featuring the highly efficient pressure-assist technology, you can rest assured that the Sloan C-100500-K Flush Cartridge will offer you a very high performance. Not only that, but the pressure-assist technology will also help boost water economy, thereby saving you money on water bill at the end of each month. In fact, apart from being popular among consumers, this product is also popular among toilet manufacturers around the world.

Furthermore, the C-100500-K Flush Cartridge is made with durable, plastic materials, which means it is capable of enduring the rigors of daily use. It also comes with a set of screws and instructions, which allows for a very easy and straightforward installation. You don’t even need to hire a professional in order to install the flush valve as the instruction that comes with it is self-explanatory.

To offer you peace of mind on your purchase, this flush cartridge is backed by a three-year warranty. The Sloan C-100500-K Flush Cartridge doesn’t have many when it comes to shortcomings. However, a lot of customers have complained about receiving faulty or defective products, something the manufacturer must pay some attention to.

What are its best features?

  • Easy to install
  • Water economy
  • Comes with a set of screws
  • Easy-to-understand instructions
  • High-performance

What could be improved?

  • Many defective units

American Standard 3174.105-0070A ChampionBest for Two-Piece Toilets

  • Size: 14 x 5.5 x 5.5’’
  • Material: plastic, metal chain
  • Weight: 1 lb
  • Warranty: 1-year limited

More features: 3.4’’ chain length, 7’’ tube

With its super quiet operation, it wouldn’t take much time to notice that the American Standard 3174.105-0070A Champion is a rather unique model. Featuring a special design that improves valve durability and toilet performance, there are many reasons to choose this model. Besides, it has an adjustable height, which makes it a universal part that is compatible with any size and tank – simply adjust its height and it is all good.

Much has been said about how other flush valves are difficult to install but not this one. It’s incredibly easy to install – all you need to do is just to read the instructions and adhere to the steps. Regardless of your knowledge level on plumbing, you can properly install it within ten minutes. Moreover, this part adheres to American and OEM Standards of replacement parts.

When you flush out, many inches of flushing water will remain inside the water tank to improve flush power. To put it simply, this unit leaves some water in the tank rather than emptying it completely which often occurs with low-quality valves. This feature enhances high pressure, and allow you to save some water inside the tank and utilize it when the need arises.

What stands out?

  • Quiet operation
  • Easy to install
  • Universal replacement parts
  • Meets OEM and American standard
  • Highly durable

What cons did we manage to find?

  • Not an ideal replacement part for other brands

Fluidmaster 400AH PerforMAXBest Value

  • Size: 12.5 x 4.5 x 3.5’’
  • Material: plastic
  • Weight: 11 oz
  • Warranty: 7-year limited

More features: silent filling, adjustable height

Undoubtedly, the Fluidmaster 400AH PerforMAX is one of the most powerful and most popular toilet flush valves on the market today, despite being a budget-friendly option. There are so many reasons to consider going for this valve, with it being universal and being compatible with most toilet brands one of its major selling points. Besides, the Fluidmaster 400AH PerforMAX comes with the PerforMax technology which allows it to activate much quicker than regular flush valves. Not only that, but it can also control your water usage thanks to its flexible roller clamp.

Also, this model of flush valve is water economical and doesn’t make any noise, which might make it appealing to many buyers. And if you are worried that you might not be able to install it yourself, discard that worry immediately as installing it doesn’t even need you to hire a professional. What’s more, this unit also allows for a higher fill rate than the majority of standard models, which allows it to save you water while filling fast.

The Fluidmaster is also backed by a seven-year manufacturer warranty, which gives buyers a lot of peace of mind on their purchase. But for all the great things we have said about this product, it would be bad to fail to mention that its flow rate is not adjustable, which might be a cause of concern for some prospective buyers. Also, the valve is slow and might take up to ninety seconds to fill.

Why did it make our list?

  • Affordably priced
  • Water economical
  • Adjustable valve shank design
  • Optimum toilet performance
  • Comes with a seven-year warranty
  • Easy to install

What is not ideal about it?

  • Non-adjustable flow rate
  • The valve is slow and takes ninety seconds to fill

Things to Consider

Except you are a professional plumber or an experienced toilet owner, choosing the right toilet flush valve is never easy. In order to save you from any quagmire, we have prepared the guide below.

Learn the basics – how does a toilet flush valve work?

Best Toilet Flush ValveMost toilet users don’t have any idea when it comes to how a toilet flush valve works and it is understandable. Most toilets never break, and if your toilet does not break, there will never be anything for you to fix, which means you won’t have any idea on how exactly it works. However, it is quite important to have a grasp regarding how a toilet functions because sooner or later, your toilet will break someday. If you’re looking to understand how your toilet flush valve works, then pay attention below:

  • The toilet tank can hold about two gallons of water.
  • So the flush valve is set up to hold and discharge that water as at when required.
  • As soon as the toilet tank is empty, the flush valve will return to its previous position, thereby closing the drain over again.
  • The fill valve is an additional security mechanism, which makes sure that the tank does not overflow and flood your bathroom.
  • The filler valve works according to the filler float that makes the filler valve to close the drain when it reaches a particular height due to the increase in the level of the water.

Tips on installing a toilet fill valve

Installing a toilet fill valve is something that everyone has to learn how to do by themselves. While the process is not difficult, it is fairly complex since there are a couple of steps to adhere to. Below are the steps to follow when installing a toilet fill valve.

  • Turn the valve clockwise to shut the water off and then remove the lid from the water tank.
  • Completely drain the water.
  • Loosen the lock nut that keeps it in position by removing the fill valve, placed under the tank.
  • Get the new one ready, by adjusting the height as per your needs and fastening the rubber washer.
  • Insert the flush valve in position and use the embedded mechanism to lock it.
  • Attach the tube for water supply to the toilet tank and the tube for the refill to the overflow pipe.
  • Carry out a test on the flush valve and check for any possible leaks.

We are confident that the guideline above is simple and easy to follow, and will help get the job done as quick as possible. All you require is a little patience and some know-how.

Features to consider while choosing the best toilet fill valve

There are three primary problems that every toilet owner has to deal with: noisy filling, a weak flush, and leaky valves. Each of these issues can cause more issues. While upgrading your toilet fill valve can offer a simple fix, there are much better models you can find on the market. However, there are some factors you must consider in order to know which model to go for. The most important out of those factors are below:

Type of a ballcock or plunger

The ballcock or plunger is an old type of fill valve, and it’s usually composed of a brass arm and a float ball. This type features a brass sealed off with a rubber washer and affixed with a ballcock valve. When spoilt, you can only “fix” it by buying a new rubber washer. So far all the components come out in a single piece, then its fine.


The diaphragm style valve, on the other hand, comes mostly with plastic. While the float arm and the ball appear similar to plunger’s, repairing the diaphragm style could be a bit difficult. Having said this, you can only buy a replacement for it. Fortunately, they are usually very affordable, so replacing them every now and then shouldn’t be a problem.

Floatless ballcock

Best Toilet Flush ValveAlso referred to as the cupless style, the floatless ballcock is capable of sensing the level of the water from the tank’s bottom with the aid of its diaphragm. In fact, it has a perfect size for low-profile tanks. Besides, the floatless ballcock is extremely easy to adjust. You can effortlessly do this by just turning the screw at the top of the valve.

Cup Type

The container type of fill valve is the last, and it is the latest among all the types available. When you purchase a new toilet, the odds that you will see the cup type are very high. The impressive thing about this type of fill valve is that it has an adjustable size, making it a universal type. As far it’s anywhere in the range of seven to thirteen inches, you’re already set.


Best Toilet Flush ValveOf course, a fill valve cannot fit every toilet. For example, most models are not compatible with primitive toilets. Make sure you check the height and dimensions to ensure that your fill valve is compatible with your toilet. You can even choose a model with an adjustable height like the KOHLER GP1083167 and TOTO Combo Kit to remove any doubt.

Materials it’s made of

Choose a model that is made with durable material. You can opt for high-quality rubber and ABS materials, which are highly resistant to corrosion. It is important, particularly for expensive toilets.


Of course, nobody wants everyone to know when they are using the toilet, which is why the noise is an important factor as well. Go for a quiet toilet flush valve such as the American Standard 3174.105-0070A Champion. Most of the most recent models actually operate quietly.


It’s also important to choose a toilet flush valve that is backed by a warranty. Sometimes, you just cannot predict these products, which is why you need to go for a model with a warranty, just in case anything goes wrong. An example of a model with a good warranty is the Fluidmaster 400AH PerforMAX, boasting a seven-year warranty.


Your toilet flush valve might be faulty when you start noticing one or all of the following signs: noisy toilet, slow refilling or the tank won’t even refill at all, or leaking or running toilet. When your toilet starts making sounds when you’re not using it or producing humming noises immediately after use, then something might be wrong with the tank. Try to open it immediately to diagnose the problem.

Another sign is when your toilet starts refilling slowly or won’t even refill at all, then you might need to change the flush valve. The last sign is when your toilet starts leaking, which might consequently lead to a spike in your water bill.

And if you’re wondering, you can actually fix a malfunctioning valve. If the toilet valve does not properly seal because it isn’t seating properly, follow the steps below to fix it.

  • Turn your water supply off using the shut-off valve.
  • Flush your toilet and hold the handle for a little while to ensure that no water is left.
  • Utilize a rug or sponge to mop any remaining water in the tank’s bottom.
  • Find the seat of the valve and clean it before attaching a sealant ring on top of the drain seat.
  • Put everything back and test.

Your toilet flush valve may just be dirty, and not damaged. Being dirty can prevent a valve from closing appropriately, thereby allowing water to leak. In this circumstance, you don’t have to purchase a new one, just clean it.

  • Turn your water supply off with the aid of the shut-off valve.
  • Flush the toilet and hold the handle for some time to ensure that no water remains.
  • Mop the remaining water in the tank’s bottom with the aid of a rug or sponge.
  • Find the valve seat/flapper and give it a thorough cleaning.
  • Attach a sealing ring on the top of your drain seat.
  • Fix everything back and test.

Our Verdict

Kohler is one of the biggest brands in the sphere of plumbing, which is why it shouldn’t come as a surprise to anyone that we have chosen one of their most popular products, the KOHLER GP1083167, as the best toilet flush valve. Being water economical, adjustable, and boasting a durable construction, you’ll be hard pressed to find someone that will argue against our choice.

Our second choice and third choice are the TOTO Combo Kit and the Fluidmaster 400AH PerforMAX respectively. Both are powerful, quiet, durable, easy to install, and adjustable, making them worthy picks. In addition, the Fuidmaster is very affordable, which makes it appealing to people on a budget.

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