Buyer's Guide & Information

7 Best Dual Flush Toilets For Water Conservation & Efficiency

Dual flush toilets are a great way to lower water bills for your home and contribute to the environment. Here is your guide to saving water in 2019!

by PlumberAndy

Buyer's Guide & Information

7 Best Dual Flush Toilets For Water Conservation & Efficiency

Dual flush toilets are a great way to lower water bills for your home and contribute to the environment. Here is your guide to saving water in 2019!

by PlumberAndy

by PlumberAndy

It’s obvious to say, but one of the most important decisions you can make when designing a new (or upgrading an old) bathroom is which toilet would be best.

In the past, it was relatively simple. All toilets do the same thing, so it was more a matter of style and design than with having a choice of functionality. Nowadays it’s common to consider dual flush toilets as a viable option as well as traditional single flush models.

What can a dual flush toilet do for you? Are they worth it?

Look no farther! We have looked at many of the dual flush toilets on the market today to help make your buying decision as comfortable as possible. Before we get to the reviews, though, we should take some time to discuss dual flush toilets and what they are all about.

Understanding Dual Flush Toilets

The most significant difference between a dual flush and a single flush toilet is relatively simple.  A dual flush toilet gives you the choice of two different flushing modes, each with a differing amount of water being used.  The flushing option that uses the most water is meant for the removal of solid waste, and the other mode uses less water to handle primarily liquids.

The initial design for dual flush toilets came from Australia in the mid-1970s, with the first commercial models being offered in the 1980s.  From there, use of them as a standard proliferated through many countries, leading them to be a readily available option all over the world as of today.

Woodbridge Dual Flush

3 Benefits of Using Double Flush vs. Single Flush Toilets

There are several benefits with using a dual flush toilet over a single flush model:

Water Conservation

The biggest advantage is saving water.  Single flush toilets use the same amount of water, regardless of what is being flushed.  With a dual flush toilet, the larger flush uses 6 liters while the smaller flush uses only 3.  

In comparison, a typical single flush toilet (manufactured after 1994) uses a maximum of 6 liters (1.6 US gallons). Older models can use upwards of 20 liters!

Cost Savings

The first benefit leads to the other.  If you live in a municipal area, you most likely have to pay a monthly water bill. Reducing the amount of water used means you aren’t spending as much – and that’s always a good thing in my book!

Reduced Maintenance

The design of a dual flush toilet uses larger waterways internal to the toilet.  That means you’ll have much less of a chance for the toilet to get clogged and backed up.  No clogging means no overflows, which means you will have a far less likelihood of ever having a nasty – and potentially hazardous – mess to clean up.


Choosing the Best Dual Flush Toilet

All dual flush toilets aren’t made the same.  Today you will find a large number of options and design features that can make it difficult to pick out the one that would be best for you.  Let’s discuss some of the options you may come across; having a good understanding will help you with your buying decision.

Toilet Bowl

For the most part, dual flush toilets come in the same general shapes that you will find with single flush units:

  • Round
    The smaller front-to-back dimensions make them a good choice when you don’t have much room (as within a smaller bathroom).
  • Elongated
    With a front-to-back measurement that is greater than a round toilet by a few inches, elongated toilets are typically more comfortable and easier to use.
  • Height
    Standard bowls are in the 14 to 15-inch range (measured from the top of the toilet to the floor). There are also styles considered “comfort height” that go from 17 to 19 inches. A few inches may not sound like a lot, but it can make a big difference with getting on and off comfortably.

Design & Style

The design and style of the right toilet for you goes beyond what shape the bowl is.

  • Materials
    The right material used to construct the toilet isn’t much of a decision point.  For the most part, your best choice will be porcelain or…porcelain!  Porcelain offers the best way to meet all of the needs of a toilet. It’s waterproof, can be cast into complex shapes, it’s relatively stable with temperature changes, and it’s very sturdy.  Plus it’s easy to clean since the finish makes it non-porous (keeping nasty stuff from growing over time). Plastics and steel constructions can meet some of these requirements, but typically not all of them.
  • Aesthetics
    How a toilet looks is more or less important based on how you plan on using it.  Do you want a beautiful, stylish piece to fit within a specific bathroom décor within your home? Then a fancier visual design (typically an elongated bowl) would be your best choice, and you can also select from a range of colors as well. If you are looking for simple functionality in an industrial or commercial setting, then a plain old white toilet will be good enough.

Flushing Methods and Mechanisms

  • Methods
    There are two general methods to flushing a toilet properly. The first is good old gravity. The force of water flowing down from the tank into the bowl (coupled with – in some cases) a siphoning effect is what clears the contents through the trapway into the drain. There is also the pressurized method as well.  Here there is extra water that is pressurized and used to “assist” the flow of water coming out of the tank, therefore increasing the intensity of the flushing action.
  • Mechanisms
    You’ll typically find two different devices to activate a dual flush toilet: the traditional toilet lever or a push button located on the top of the tank. With the toilet lever, toggling the lever either up or down will determine which volume of flush you will get. This may take a little getting used to as we are typically used to always pushing the lever down to flush. With the push button, you may note that the button itself is actually two buttons next to each other, with each being used exclusively for either the larger or, the smaller flush.

Water Usage & Conservation

Water Conservation

As we already discussed, saving water is probably the most significant benefit of installing a dual flush toilet. 

For example: using a dual flush toilet at the average max flush volume of 1.6 gallons per flush as compared to an older toilet that uses 3.5 gallons per flush can result in saving over 50% on your annual usage. 

And that’s not considering the lower volume flush meant to handle liquid waste!  That becomes even more of a factor when you consider that an average person urinates 6 to 8 times a day (as compared to as low as once a day for producing solid waste).

It’s easy to see how fast the water savings can add up!

Trapways

One design feature that is a significant benefit of dual flush toilets is the size of the trapway (the trapway is the path that the toilet’s contents take from the bowl to the drain when it is flushed).

Trapways are typically larger in diameter on a dual flush toilet. This makes it easier for solid waste to flow and not clog as much as it may with a traditional toilet. It also lets the toilet use less water and flush more efficiently.

From an appearance standpoint, there are several types available. 

  • Visible
    This is the style that you may typically see the most. With a visible trapway toilet you can see the path of the trapway behind the bowl. These can be difficult to keep clean because of all the extra surfaces that dirt and debris can settle into.
  • Concealed
    With a concealed trapway the area behind the bowl is covered up, giving you a sleeker appearance and it can be much easier to clean.
  • Skirted
    Toilets that are considered “skirted” have a clean look from the back to the front. You mostly can’t see either the shape of the trapway or the contour of the bowl itself.

It’s important to note that these options affect only how a toilet looks from the outside.  They don’t have any effect on how the trapway itself operates, or how it looks when you are staring at the bottom of the bowl. Deciding on which type to go with is purely a matter of style.

Drain Location and Installation

The drain location from the bottom of the toilet is usually not much different than that of a standard single flush toilet. 

Keeping that point in mind there may be some dimensional differences between the two models, though, so it is always best to verify how a new toilet will fit with the existing drain hole in the floor (for example, the drain hole may be too close to the wall for a different style toilet).

That being said, the overall installation process for a toilet is something that may be best left to a plumber, depending on your level of knowledge and skill.  You may end up with fitment and leaking problems if it’s not done right - some jobs are best left to the pros!

There also are different styles of installation as well. Most toilets you will see are mounted directly to the floor, while some are designed to attach to the wall.

Certification

It’s always best to look for dual flush toilets that are certified as WaterSense compliant.

WaterSense is a certification from the United States Environmental Protection Agency, and only models that meet the EPA’s stringent standards for water use efficiency are eligible.  Per the EPA’s website:

Products bearing the WaterSense label:

WaterSense Promotion Label
  • Perform as well or better than their less efficient counterparts
  • Are 20 percent more water efficient than average products in that category
  • Realize water savings on a national level
  • Provide measurable water savings results
  • Achieve water efficiency through several technology options

Warranty Coverage

A general rule of thumb with any commercial product is to always look for the model that will give you the best warranty coverage – the longer, the better.

Limited warranties can vary between manufacturers, and you need to educate yourself on what is covered.  For example, some toilets may have a 10-year warranty on the bowl but only a year on the toilet seat itself.  A comparable model may have a better – or worse – warranty level. 

It’s always best to read the fine print as a warranty can be the deciding point between two models that are relatively similar in features, quality, and price.


7 Best Dual Flush Toilets Reviewed

1. Woodbridge Luxury T-0737

Best Dual Flush Toilet

Water Consumption (gallons per flush)

1.0/1.6

Shape

Elongated

Style

1 piece

Size

31” x 18” x 28”

Weight

152 lbs.

Certification

None

Warranty

Five-year/one-year limited

Topping our list of the best dual flush toilets is the Woodbridge T-0737 Toilet & Bidet Luxury Dual Flush Toilet.

The sleek skirted design gives a modern flair to any bathroom, giving you clean lines that are easy to keep clean.  But the way it looks is only the beginning…

The Woodbridge T-0737 comes with a bidet seat as a standard feature (a bidet is a feature where water can be aimed to rinse and clean your body off after use, while still sitting down). It’s much more than just some water shooting at you, though. 

There are three different settings, each with adjustable water pressure – and they all use filtered water for extra hygiene.

The water from the bidet is heated and so is the soft, cushioned seat – giving you the ultimate comfort level.  The seat itself has hinges made out of top-quality stainless steel, guaranteeing you years of smooth operation without the chance of ever corroding or rusting out.

The dual flush system is designed for a typical 1.0 gallon small and 1.6-gallon large flush, ensuring water conversation and savings with every flush.

When you consider the five-year warranty on the porcelain (and the one-year warranty on the mechanical parts and toilet seat), it’s easy to see why the Woodbridge T-0737 Toilet & Bidet Luxury Dual Flush Toilet has earned its spot as our choice for the best overall dual flush.

Woodbridge customer Billie says it all simply: "This toilet is well worth the money!"

Pros
  • Modern skirted design
  • High-efficiency dual flush
  • Bidet seat as standard equipment
  • Cushioned seat with stainless steel hinges
  • Five-year/one-year limited warranty
Cons
  • Flushing buttons may stick
  • Installation may be difficult

2. Galba Compact Mini-Commode

Best Compact Dual Flush Toilet

Water Consumption (gallons per flush)

0.8/1.6

Shape

Elongated

Style

One-piece

Size

24.5” x 13.5” x 28.5”

Weight

90 lbs.

Certification

None

Warranty

-

Dual flush toilets come in many sizes and shapes, giving you the ability to have a dual flush capability in a small package. The Galba Compact Bathroom Mini-Commode is our choice for the best compact dual flush toilet and is perfect for small bathrooms.

For installations where room may be tight, the Galba Mini-Commode offers many of the same features and functionality that you’ll find in larger models. Water conservation is the name of the game here, with a conservative 0.8-gallon small flush to handle liquids (along with a more standard 1.6-gallon large flush).

The stylish one-piece, concealed trapway design gives it a modern appeal, and makes it much easier to clean than a traditional visible trapway toilet. The glazed surface was designed to not scratch, fade, or accumulate rust stains.

The plastic seat could be a little more robust, particularly for larger and heavier people.

But don’t let the small size fool you - it is just as effective in removing waste as many of the larger models.  All in all, the Galba Compact Bathroom Mini-Commode packs just about as much punch as its big brothers do!

Pros
  • Small enough to fit in tight spaces
  • Same dual flush capability as bigger models
  • Reports of excellent customer service
  • Powerful flush for its size
Cons
  • Compact size may be too small for adults
  • The plastic seat may lack durability

3. Toto Neorest

Best Dual Flush Toilet with Advanced Technology

Water Consumption (gallons per flush)

0.8/1.0

Shape

Elongated

Style

One-piece

Size

32.5” x 15.5” x 21.5”

Weight

124 lbs.

Certification

WaterSense

Warranty

Three-year limited

Technology is a beautiful thing, and nowadays just about every commercial product has some upgraded model that benefits from it. This is indeed true with our pick for the best dual flush toilet with advanced technology – the Toto Neorest Dual Flush Toilet.

The Toto Neorest utilizes a proprietary Tornado Flush system, which uses pressurized nozzles to create a cyclone effect with each flush. This not only makes the flushing cycle more powerful and efficient but it also keeps the inside of the bowl clean as well.

Water conservation is at a premium with the Neorest, with the small flush being 0.8 gallons and the large being only 1.0 gallons. It doesn’t sound like much, but with the Tornado Flush system, each flush may be more efficient than a typical dual flush toilet. It is also WaterSense compliant as well, so you can be assured that you will be helping the environment.

Toilets, by their nature, could be considered unsanitary. The Neorest does everything in its power to keep hygiene levels where they need to be. Their CEFIONFECT ceramic glaze creates a surface that may be smoother than competing models, which helps prevent contaminants from sticking to the bowl. In addition, the EWater+ system uses electrolyzed water to act as an agent that helps to remove residual waste.

If that isn’t all fancy enough, the Washlet system has an adjustable spray to provide discrete, intimate cleaning with temperature-controlled water.

Technology doesn’t mean much if the unit is…well…ugly. Toto takes care of you here as well with an attractive skirted, one-piece design that would be welcome in just about any bathroom.

Add in an automatically operated lid, automatic flushing, a night light, and remote control (yes…there is such a thing as a remote control for a toilet); it’s no wonder that the Toto Neorest is our pick in this category.

"An integrated toilet with technologically advanced WASHLET, this Neorest is a truly remarkable combination of ecology and luxury." - Toto

Pros
  • Tornado Flush system for effective flushes
  • WaterSense compliant
  • CEFIONFECT ceramic glaze for increased hygiene
  • EWater+ system for easy cleaning
  • Washlet for intimate washing
Cons
  • Expensive purchase price
  • Needs access to an electrical wall outlet

4. Toto Aquia Wall-Hung

Best Wall Mounted Dual Flush Toilet

Water Consumption (gallons per flush)

0.9/1.6

Shape

Elongated

Style

Wall Mount

Size

23.8” x 15.8” x 17.5”

Weight

66.5 lbs.

Certification

WaterSense

Warranty

One-year limited

Most typical toilet installations are done with toilet models that are bolted directly to the floor. There are other options, though, such as using a wall mounted unit. This is precisely where the Toto Aquia Wall-Hung Dual Flush Toilet comes into play as our selection for the best wall-mounted dual flush toilet.

First off, let’s dispel a concern that you may have – yes, a wall mounted toilet can be strong enough to accommodate an adult’s weight. It’s important to note that the installation must be done correctly and may be best left for a professional.

Featuring WaterSense certification, the Aquia is certain to conserve water with the Toto Dual-Max flushing system. The Dual-Max will provide a robust and efficient flush of both a 0.9-gallon small flush and a 1.6-gallon large flush.

Hygiene and cleaning concerns can be minimized thanks to the CEFIONFECT ceramic glaze. This proprietary finish claims to be smoother than typical, similar finishes – which makes it harder for waste products to stick to the bowl.

The skirted design matches well with the wall-mounted design. This adds a level of style to your bathroom that you may not find with a traditional floor mounted toilet.

If you’re looking to install a tremendous dual flush toilet with a visual appeal that is different from most, then the Toto Aquia Wall-Hung model may be your model of choice.

Make sure to read our full guide to Toto brand toilets, found here. 

One Wayfair customer remarks, "I love the fact that it's wall mounted, easy to clean under (nor dirt circle around the base), no ugly bolt covers, modern design without showing all the twists and turns of the ejection system." 

Pros
  • CEFIONFECT ceramic glaze for improved hygiene
  • WaterSense certification
  • Attractive and strong wall-mounted design
  • Efficient Dual-Max flushing system
Cons
  • Seat and wall tank not included
  • Installation may be difficult

5. American Standard H2Option Siphonic

Best Water Saving Dual Flush Toilet

Water Consumption (gallons per flush)

1.0/1.6

Shape

Round

Style

Two-Piece

Size

27.8” x 15” x 29.5”

Weight

57 lbs.

Certification

WaterSense

Warranty

Two-year limited

When it’s all said and done, water conservation is the biggest reason why most people install dual flush toilets. You can be assured of helping the environment by using the American Standard H2Option Siphonic model – our option for the best water saving dual flush toilet.

The specifications for the dual flush (1.0 gallon & 1.6 gallons) may seem similar to other models, but what sets the H2Option apart from the competition is the siphonic action technology. The “jet-powered siphon” system uses a bowl jet to add water in addition to water that flows from the rim. This adds to the flushing power while retaining the water level while flushing, which can help keep the bowl clean.

Did I mention that it’s WaterSense compliant as well?

Another great feature is the PowerWash rim. This creative design allows water to flow into the rim chamber while trapping air, creating a pressurized condition. The water is then deposited in the bowl during the flush with more power than a traditional toilet.

Installation is much easier thanks to the American Standard Speed Connect system. With Speed Connect, installation time can be reduced up to 30% by using factory installed and pre-assembled parts.

Keeping toilets clean can be a challenge, and the EverClean surface will be your best friend! The finish is antimicrobial – and that will help to keep nasty mold, mildew, and bacteria from growing.

With all of these great features, it’s clear that the H2Option is much more than just a fantastic water saving toilet!

Pros
  • Siphonic flushing system
  • WaterSense compliant
  • PowerWash Rim for increased water pressure
  • Speed Connect system for easy installation
  • Antimicrobial EverClean surface
Cons
  • The seat is not included
  • Fill valve may malfunction

6. Swiss Madison St. Tropez

Best One-Piece Dual Flush Toilet

Water Consumption (gallons per flush)

0.8 or 1.28

Shape

Elongated

Style

One-piece

Size

26.6” x 15” x 31”

Weight

120 lbs.

Certification

None

Warranty

-

So…let’s say that you plan on remodeling your bathroom, and you want to update the look and design of the entire room completely, then without a doubt, a sleek one-piece toilet is the way to go. 

Better yet, what if that stylish new toilet also was one of the most efficient dual flush toilets around?

With the Swiss Madison St. Tropez, you may find it’s exactly what you’re looking for, and with good reason – it’s our selection for the best one-piece dual flush toilet on the market.

One of the best features of the Swiss Madison is the efficiency of each flushing mode. With a small flush of 0.8 gallons and 1.28 gallons for the large one, you’ll conserve more water than with a typical dual flush toilet.

Style is the name of the game with the St. Tropez, as it boasts a smooth, skirted trapway design that adds that modern touch. It also comes with a padded seat with quick-release hinges, which is a great feature to help keep things clean.

Some one-piece toilets may be challenging to install because all of the fasteners are covered up (to maintain a clean appearance). With the St. Tropez, installation is made much easier thanks to unique holes designed for easy access to the mounting bolts.

Modern flair meets efficiency – welcome to the Swiss Madison St. Tropez!

Pros
  • Modern design for a sleek appearance
  • Efficient dual flush water volumes
  • Soft seat included
  • The seat is easily removable for cleaning
Cons
  • Water may spray out when the lid is open
  • The plastic lid could be more robust

7. Kohler Wellworth 

Best Two-Piece Dual Flush Toilet

Water Consumption (gallons per flush)

1.1/1.6

Shape

Round (elongated available)

Style

Two-piece

Size

39” x 34.5” x 24.5”

Weight

86.3 lbs.

Certification

WaterSense

Warranty

One-year limited

The flashy style that a one-piece toilet can give you certainly isn’t for everyone. Sometimes a good old traditional-style two-piece toilet is all that you need. Our pick for the best two-piece dual flush toilet is the Kohler Wellworth.

Brought to you by a company that has been trusted for quality products over many years, the Kohler Wellworth does away with many of the fancy features that other dual flush toilets may have. To be sure, more benefits and features are not necessarily a bad thing. It’s just that sometimes the basics are all you need – and the Wellworth certainly delivers.

Featuring a side-lever flushing mechanism, the Wellworth has Kohler’s Class Five flushing technology. With Class Five, a large flush valve helps to release more water coupled with water also being fed to a special jet. This increases flushing efficiency along with helping to keep the toilet clean.

One area where installation of two-piece toilets can be troublesome is where the tank meets the bowl. Sometimes it’s hard to get things just right where there isn’t any leaking. With the innovative DryLock system, all you need is a socket wrench to get a foolproof, no-leak seal.

The Kohler Wellworth isn’t the fanciest dual flush toilet on our list, but it certainly has enough features to be our choice in the two-piece dual flush toilet category.

"Easy to install. I wasn't sure about the dual flush option, but have been pleasantly surprised. It has been about two weeks and no issues. Even our almost five year old is operating the handle with ease! " - A 5-Star review on Lowe's website

Pros
  • Simple, traditional design
  • Class Five flushing technology
  • DryLock system for leak-free tank/bowl installations
  • Side-lever flushing mechanism
Cons
  • The seat is not included
  • Flushing may be noisy

How to Use a Dual Flush Toilet

There’s nothing tricky or complicated about using a dual flush toilet.  The key is knowing what a dual flush toilet actually does. That’s the voice of experience here - I have run across them before and didn’t understand why I would have pushed one button over the other…

It is as simple as this: larger flushes for solid waste and smaller flushes for liquid waste.

If you have a dual flush toilet, it may help to let your guests know how to use it – you may avoid some potentially embarrassing situations!


Cleaning and Maintenance

There isn’t a whole lot of difference with cleaning and maintaining a dual flush toilet over a single flush model.

Keep your bowl clean on the inside with a good toilet bowl cleaner (one that disinfects) and a quality toilet brush. Take care to clean up under the rim as well. The outside of the bowl should be cleaned as well, but that can be done with a disinfecting spray as compared to the stronger bowl cleaner.

Maintenance is best done proactively. By that, I mean you should take a look at how things are working periodically so problems can be fixed before they become bigger issues. Cleaning buildup that can accumulate from your water over time is one of the best things you can do. 

This is especially true if you have “hard water” that can produce rust, scale, and mineral buildup. This can get into the mechanisms and components of a toilet and can make them not work as they should.

Also, you should take a look for leaks every now and then. Valves can (and will) fail!  You may also run into cases where the toilet bowl itself may have shifted on the floor, causing the seal between the bowl and the floor to go wrong.


Frequently Asked Questions

Are dual flush toilets worth it?

The benefits of a dual flush toilet can certainly outweigh a single flush unit, with the biggest one to consider being the amount of water you can save (and, therefore, not pay for). They may be more expensive upfront, but your water bill savings will offset that over time.

What button should I push in a dual flush toilet?

It depends on whether or not you are attempting to flush solid waste or liquid waste. The button that gives you a larger flush should be used when getting rid of solids. Liquid waste removal is typically most efficiently done with the one that uses less water.

How much water do dual flush toilets save?

That all depends on what kind of toilet you are using as a reference. If you had an older home that, in some cases, uses up to 20 liters per flush, then a dual flush toilet can use almost seven times less water (based on a lower dual flush setting of 3 liters).

It’s important to remember that even newer, high-efficiency single flush toilets (using around 6 liters per flush) use that amount with every flush – regardless of the type of waste you are trying to eliminate. With a dual flush toilet, you always have that option to use less per flush.

How do you fix a toilet that flushes twice?

There are two fixes that will typically fix a toilet in this case:

  • Look at the flapper
    Lightweight or sticking toilet flappers (the piece at the bottom of the tank that allows water to flow into the bowl) may not be operating as they should, letting more water flow – giving you that extra flush. Use a heavier flapper or make sure that nothing is restricting the one you have from moving freely.
  • Look at your level
    Too high of a water level in the tank will lead to too much water flowing into the bowl before the flapper can shut, causing a dual flush. Most new fill valves (located in the tank) will allow you to raise or lower the overall level to give you the best operation.
What makes a toilet flush stronger?

A toilet can produce a stronger flush by either maintaining what you have or by buying one that has a different design.

Maintenance can involve increasing the water level in the rear tank, which will give more pressure due to the added weight of the extra water. Also, there are a series of holes around the underside of the toilet bowl rim. Over time these can become clogged up with debris or scale, making them less efficient. Periodic cleaning can help to maximize water flow as much as possible.

From a design standpoint, you could also buy a pressure flush style toilet. These are designed to have a bladder that holds pressurized water that helps to give a stronger flush. On the flip side, there are vacuum flush designs as well that are meant to operate in reverse of pressure models (suck the water out instead of pushing it out).


Conclusion

Dual flush toilets are a great way to conserve water, and with the many feature-filled models available you’re sure to find one that is the best fit for your needs. Hopefully, you are much more informed on what dual flush toilets are and how they work.

Our #1 pick of the Woodbridge T-0737 Toilet & Bidet Luxury Dual Flush Toilet checks all of the boxes and is certainly worthy of consideration when making your buying decision.

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