Best 6 Dual Flush Toilets with Partial Flush – Save Water Review

Dual flush toilets provide you the choice between two flush options, saving your overall water usage. The partial flush uses about half the amount of water as a full flush, resulting in water savings compared to other types of toilets.

Keep reading to get a better understanding of how the best dual flush toilets work, and reviews of our favorites!

Top Dual Flush Picks

›	Editor's Choice:Editor's ChoiceWe pick our favorite model based on style, function, customer feedback, and cost effectiveness.	Kohler Wellworth
›	Most Water Efficient:	TOTO Drake
›	Highest Flush Score:Highest Flush ScoreWe chose the highest MaP score as the winner.	TOTO Drake + Washlet S500
›	Budget Friendly:	American Standard H2Option
›	Most Reviewed:	Swiss Madison St. Tropez
›	Runner Up:	TOTO Aquia IV

Dual Flush Button Explained

In most cases, a dual flush toilet will have  two buttons  – a larger and a smaller one. Each button has a purpose.

For liquid waste, you simply press the smaller button and hold it for a short period of time.

For solid waste, you will either press the larger button or press both buttons together, depending on the toilet, which will activate a full flush.

If the small flush is not enough, you can immediately press the large button. However, it might take some time to refill the cistern after the small flush. Depending on the pipes, it can take a few seconds or even up to several minutes before you can flush again, like other toilet models. However, if you’re focused on reducing water use, try to avoid flushing multiple times if possible.

You may also encounter a dual-flush toilet that has a lever instead of buttons. Even though the mechanism is different, the principle is the same – press the lever halfway down for a small flush and all the whole way down for a full flush.

 

Reviews of the 6 Best Dual Flush Toilets (2023)

Our experts searched for the top dual flush toilets on the market to review and listed their facts.

1. Kohler Wellworth Toilet – Editor’s Choice

The Kohler series is known for its exceptional flushing performance, and the Wellworth toilet is no different. 

It features a left-side nested trip lever that allows you to conveniently flush the toilet, even while sitting on it, and thankfully, we’ve not received any complaints on splashbacks like most toilets, which is probably why Amazon highly rates this one.

The Wellworth toilet is a classic, using the Class Five dual flush system, well known for its bulk flushing performance. Its 1.6/1.1 gallons per flush system is WaterSense-approved, and you might be getting rebates on your water bills with this toilet. 

Its flush system comprises a direct-fed siphon-jet flush, a 2 1/8 inch, fully glazed trapway, and a large round canister valve. The canister valve and siphon jet deliver a quick, powerful water gush from all sides of the bowl, and the glazed trapway works with the siphoning system to forcefully but quietly expel the waste. 

The canister valve also reduces leakages by protecting the seal, a definite upgrade from the 3-inch flapper, and the tank fills up pretty quickly.

However, we can’t quite wrap our heads around how a Class Five flush system gets clog complaints. Could it be a trapway issue? We can’t tell, but some customers have complained the toilet gets clogged, and sometimes they have to flush twice to clear the waste. 

Another thing is the leak-proof valve isn’t as efficient as we thought. A few users claim it does not last, and water leaks from the tank into the bowl, a flaw in its water efficiency. It relies mainly on a high gloss finish for anti-stick performance. Now, we know this is quite a lot. But a more comprehensive review would help give a better, final judgment on this piece.

Other Wellworth Models

Summary of Recent Reviews

This one has a powerful flush, according to several reviewers. For some, this was their first dual flush toilet and they wish they had bought it sooner. Customers like the modern look of this toilet, as it adds to the overall aesthetic of their bathroom.  “Works Great and Looks Great!”

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2. TOTO Drake Toilet – Most Water Efficient

TODAY’S DEAL on AMAZON

 

The TOTO Drake is one of the industry’s best and most popular flushing toilets. It is available in various forms: the two-piece, single flush, and the two-piece, dual-flush. It also comes in a round bowl and elongated bowl design.

All Drake models are coated with the CEFIONTECT glaze, making it almost impossible for waste and other residues to stick to the bowl, further enhancing its hygiene quality. But, the TOTO Drake dual flush goes a step further, a possible reason for its higher price. 

The dual-flush TOTO Drake models address the high water usage of the Drake toilets. Its 0.8/1.0 gallons per flush offering makes it WaterSense compliant and suitable for residents in all states.  

This toilet features the  TORNADO FLUSH system , which expels water from the tank through 2 powerful nozzles instead of the standard rim holes. Add that to its extra-large 2 1/8 – inch, semi-concealed, fully-glazed trapway, and it becomes clear why it is the Most efficient.

The faster the water enters the bowl, the stronger the siphoning effect in its trapway. The stronger the siphon power and the larger the trapway, the better the cleaning power and the lesser the clog and discoloration risk. 

Other exciting features of this toilet include: the relatively quiet and discreet flush and the fast-filling tank – it takes just about 35 seconds. Its large water surface reduces the incidents of streaking and skid marks and curtails the odor of turds. 

Unfortunately, some customers have complained that the ridge in the bowl gives the impression of an ugly, bad stain. 

So, if this Drake doesn’t seem right for you, check our other TOTO Drake toilets we reviewed.

Other Drake Models

Summary of Recent Reviews

Customers are pleased with this splurge! For most, this is a comfortable toilet with a modern design.  Users like the bidet functionality and the ability to program simple functions such as opening the lid.  “This Toto is amazing and the quality is top of the line. You can’t go wrong with a setup like this.”

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3. TOTO Drake Washlet+ S500 – Strongest Flush

The Drake Washlet+ is among the best bidet innovations of the TOTO company. Although it has a lot in common with the Aquia IV, it has various unique, high-tech features.

Unlike most dual-flush toilets, the TOTO Drake + Washlet S500e uses the DynaMax™ tech. This technology utilizes 1.28GPF for a full flush and 0.8GPF for a partial flush. It has WaterSense certification and could be quite economical. 

Now, despite having a side-positioned chrome trip lever, the S500e has an automatic flush system that you can activate once you’re done with the remote control. 

One exciting thing we love about this toilet is how it addresses hygiene in a high-tech and even more efficient way. 

While it features the common CEFIONTECT glazing, it uses electrolyzed water in its flush system, which cleans the bowl even better than regular water. But, it doesn’t wait till the action is done. Before use, this toilet has a premist function that sprays the bowl with electrolyzed water to deter waste, residues, and other materials from sticking to the bowl. 

To say these are what make this toilet unique would be to undermine the TOTO Drake + Washlet S500e totally. There are many other features we can guarantee you would not see in just any toilet – a clear explanation of why S500e is one of the more expensive bidet pieces.

Other Drake Washlet S500 Models

Our team collected all Drake Washlet S500 model variations within this collection to help you compare the differences.

Model Name	Model Number	Style	GPF	Bowl Shape	Major Differences	Resources
Drake Washlet S500E	MW7763046CEGA#01	Two-piece	1.28	Elongated	TORNADO FLUSH® system. High-tech electronic bidet seat and toilet combination (1.28 GPF)	Spec Sheet
Drake Washlet S500E	MW7763046CSGA#01	Two-piece	1.6	Elongated	TORNADO FLUSH® system. High-tech electronic bidet seat and toilet combination (1.6 GPF)	Spec Sheet
Drake Washlet S500E	MW7763046CSFGA#01	Two-piece	1.6	Elongated	Universal height. 12" or 10" Rough-in. (1.6 GPF)	Spec Sheet
Drake Washlet S500E	MW7763046CEFGA#01	Two-piece	1.28	Elongated	Universal height. 12" or 10" Rough-in. (1.28 GPF)	Spec Sheet

Summary of Recent Reviews

Overall, this toilet is a perfect combination of functionality and enhanced design. It comes with many high-end features such as DYNAMAX™ TORNADO FLUSH technology and the CEFIONTECT glaze.

When it comes to functionality, this toilet lets you choose between 0.8 and 1.28 flush, both of which utilize a 360-degree flushing system to successfully clear the whole bowl of waste. With this system, you will save approximately 3500 gallons of water per year without compromising on performance.

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4. American Standard H2Option Toilet – Budget Friendly

The new American Standard H2Option is – in our opinion –  one of the best dual flush toilets . As an upgrade from the former H2Option, this toilet is more water-efficient, EPA-certified, and more consumer-centric than the last.  

There is less need to fumble around searching for a lever or a button with this toilet because it has a large chrome-plated push-button actuator at the top of the tank. This actuator controls the two flush valves, which regulate the release of either the full 1.28 gallons per flush or a partial 0.92 gallons per flush. 

We love how this toilet doesn’t settle for less. It merges a siphon-jet (gravity) bowl with a PowerWash rim that delivers water in a quick surge to all areas, even those hard-to-reach regions. It scours the bowl, so no area is left un-rinsed. 

The new American Standard H2Option is another fast-filling tank toilet, so you don’t have to wait for too long before giving the flush another go when you need to. Its EverClean surface is most lovely because it contributes to the bowl’s spotlessly clean tendency and eliminates nasty bacteria that cause odors even deodorizers would have a hard time neutralizing. 

Combating the common problem of clogs, the new H2Option has a 2-inch wide, fully glazed trapway to expel waste faster and without residues. 

The tank refills quickly, and its EverClean surface ensures the bowl remains spotlessly clean and free from smells that even deodorizers might find difficult to neutralize. Its 2-inch wide trapway is also fully glazed to prevent clogs and waste residues. 

Unfortunately, despite its gravity flush system, some customers have complained this toilet does not clear out waste in a single flush. For a more comprehensive review on the new American Standard H2Option, you should check out this post.

Other H2Option Models

Summary of Recent Reviews

Customers are happy with this dual flush toilet, stating that it has a powerful flush that does not clog easily.  Buyers like this affordable, option that has a modern design.  The comfort height is popular among users, adding additional comfort to your bathroom experience.

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5. Swiss Madison St. Tropez Toilet – Most Reviewed

The Swiss Madison St. Tropez is considered one of the best one-piece toilets of the present time because it offers the benefits of space management, aesthetic excellence, and water maximization. 

The St. Tropez is factory tested, EPA certified, and WaterSense approved. It offers premium water-management quality by featuring a proportionate dual flush option of 1.6 and 1.1 gallons per flush. Thus, you do not have to worry about not being able to use the toilet in your region. 

Now, this is not so relevant, but we almost got confused writing this review with its interchangeable form, “Swiss Madison Well Made Forever SM-1T254.” So, we thought this might help. The above name refers to the St. Tropez as well. 

Back to business – The St. Tropez features buttons on the top of the tank which you can use to activate its dual tornado flush system and have the waste successfully run through the smooth, skirted, large trapway. 

The dual tornado (Vortex™) flush comprises two nozzles that expel water in a cyclonic action through the bowl and down the trapway for better cleaning action. The great part is it gets the job done relatively quietly. As a result, the SWISS MADISON St. Tropez is powerful enough to clear the waste and quiet enough to remain under wraps. 

The St. Tropez also has a fully glazed system that extends from its bowl to its skirted trapway to ensure residues, streaks, and dirt do not affect its shiny coat and sanitary quality. 

Unfortunately, we’ve seen complaints about its flush system being quite messy – “it flushes with a splash.” So unless you close the lid, the toilet water might end on your bathroom floor. Then, a few users claim a single flush never does the trick. But, again, don’t judge a toilet by its flush system alone. Let’s talk comfort. Check this full review of the SWISS MADISON toilets for more information.

Other St. Tropez Models

Summary of Recent Reviews

While some users had trouble with tricky installation, most of them are happy with the sleek, modern design of the toilet, especially at this price. This toilet has a modern look, and the includes a soft-close seat.  Several users praised the expedience of Swiss Madison customer service.

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6. TOTO Aquia IV Toilet – Runner Up

The Aquia IV toilet has a CEFIONTECT ceramic glaze from its bowl to its skirted trapway for a smooth, ion-barrier surface that enhances its flush and cleaning performance. As a result, it is dirt, grime, waste, and skidmark-resistant and is easy to clean.

The dual-flush system is actuated by a large button on its lid that can be pressed fully to use  1.28 gallons per flush for solids flush or halfway to use 0.8 gallons per flush for fluids flush . It is, therefore, EPA WaterSense-certified and CalGreen-compliant. This means, regardless of your region, this toilet fits the standard.  

It uses the DynaMax Tornado Flush with an extra-large flush valve and two powerful nozzles that allows electrolyzed water to enter the bowl faster and with more force for better bowl scouring power.

Now, you’d expect a flush as powerful as this to make a lot of noise, but it doesn’t. Consumers have attested to its flush being relatively noiseless. 

However, this toilet lacks quality in some aspects: Consumers complain about the chrome button not lasting and the low water flush affecting its anti-stick and sanitary quality. Still, we’d advise you not to judge yet. Check out its other features before making your choice.

Other Aquia IV Models

Summary of Recent Reviews

Buyers love the sleek look of this one-piece toilet.  Some buyers do mention that the water level is a bit too low for an effective flush, however, most customers are happy with this toilet.  “Easy to clean without the molded curvatures at the base found in other models. No issues with flushing.”

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How Dual Flushing Works

To understand how these systems work, we should first clarify how a siphon works, which is the main part of the dual flush toilet. A siphon is actually a flush valve that acts similarly to a plunger. When you press the flush lever to activate a full toilet flush, the siphon sucks water, sending it through a specific diaphragm into the siphon outlet. When the water reaches the outlet, gravity takes over and draws out the remaining water until the tank is empty.

So, how does a half flush work? Imagine a straw in a cup of water, but the straw only goes halfway into the cup. Once the water drops below the end of the straw, the straw won’t be able to suck any more water, and everything below that level will be unreachable. At that point, the straw will only be able to suck air instead of water, cutting off the water supply. This situation is actually very similar to how the dual flush mechanism works.

Most toilets achieve a half flush by breaking the water suction midway through the siphon action. Basically, the siphon usually has extruded cuts at the bottom which allow air to enter and break the air-tight seal. The breach in the seal results in emptying only half of the tank instead of the full tank. 

Introduced to the Market

Dual flush toilets were designed mainly to save water. Since you only need to use 50% of the canister for a liquid flush, using a these toilets leads to significant water savings over time. And while they may seem like new technology, they were actually patented a long time ago.

The first system was developed by TOTO in 1960 and initially had two levers. It also came with a hand-washer, and the water from the hand-washer was reused for flushing. 

However, the first practical implementation of a dual flush toilet was designed in 1980, with future iterations working to further decrease the water needed without compromising on flush performance. 

EPA Rating

Overall, toilet companies are required to keep the flush capacity of their toilets below 1.6 gallons. Many manufacturers try to go below this requirement, with some toilets that are designed to only consume 1.28 gallons per flush. Toilets that are proven to flush effectively with 80% or less of the 1.6-gallon requirement qualify for EPA WaterSense certification.

This certification ensures you save on your overall water consumption each month and can even include rebates on your water bill, depending on location. When considering a dual-flush toilet, look for EPA WaterSense certification if reducing water consumption is an important factor for you.

Single Flush vs. Dual Flush

The main difference between these two types of toilets is obvious – with a single flush toilet, you can’t choose the amount of water it uses during the flush. By comparison, they give the user the flexibility to choose a partial or full flush depending on their needs with each use.

Further, installing a dual flush toilet is an excellent long-term investment since it will save your family a decent amount of money and water over time. However, you should also know that pressing buttons on a dual flush toilet might require greater force, which might be an issue for elderly or disabled people. It also requires some initial learning to make sure everyone knows which button to use for a partial vs a full flush.

We actually have a detailed article about the differences here.

Advantages of Dual Flush Toilets

One of the main advantages of best dual flush toilets are they save money over time. It might not seem like a big difference, but imagine only needing half the resources for each flush to remove liquid waste. According to the American Water Association, an average person’s annual water expenses will reduce by about $250 by using a dual flush toilet. While toilets overall are built to consume less water with each use, they use the least amount of water when compared to any other type of toilet. Another advantage is that they are very environmentally friendly. According to the EPA, around 4,000 gallons of water can be saved each year in a standard household if a dual flush toilet is installed instead of a standard one. 

Finally, another benefit that we should mention is that dual-flush toilets use gravity to force waste down a large trapway. Thanks to this design, you should experience minimal clogging with these toilets, meaning overall performance isn’t compromised even while you save on water.

Take a look at our full detailed guide about the dual flush process here.

Installing a Dual Flush Toilet

Installing them can be pretty simple if you have the necessary knowledge and tools. always check the installation guide for your specific model, but overall, here are the main steps to follow:

1. First, remove the old toilet from its current place. You can use a knife or scraper to remove the old wax ring.
2. Then, put the closet bolts from the new product over the flange.
3. Now, using a masonry drill bit, drill through the floor over the screw-hole marks carefully.
4. After that, screw both mounting blocks into the floor.
5. Put the new toilet in its place and make sure it fits perfectly over the blocks.
6. Open the toilet tank and remove the flush valve.
7. Install the tank on the bowl and carefully tighten the bolts.
8. After connecting the water supply line, you have pretty much finished the process.
9. Finally, flush the toilet a few times to make sure there is no leakage.

Be sure to check our full guide on how to install a toilet

Frequently Asked Questions

Our reader have asked many of these questions about dual flush toilets.