Toilet Advice

6 Best Dual Flush Toilets (Complete Guide & Reviews 2019)

What is a dual flush toilet? This is a mechanism which gives users a choice between two different flushing powers. The first uses less water, and is designed for handling liquid waste, which doesn't require much power. The second utilizes more water, for the purpose of higher performance, removing solid waste, and rinsing the bowl more thoroughly. Users are generally able to activate this system by choosing one of two buttons on the tank.

In this guide, we shall look at the highest rated toilets in this category. We will explore their pros and cons in greater detail, and discover how they could benefit your bathroom.

Our pick

WoodBridge T-0001

The T-0001 is made by the WoodBridge brand. A name which offers some great washroom fixtures and hardware for the home.

It's got a one piece, contemporary design that's skirted around the bowl, and is made in vitreous china. And because the exterior is smooth and there are no gaps between tank and bowl, it's easier to clean too.

Because it's highly efficient, offers users a powerful but quiet flush, and comes equipped with a soft closing seat, we think this would make a great upgrade for any modern household.

Compare toilets

WoodBridge KOHLER Veil KOHLER Highline American Standard
H2Option
TOTO Aquia Swiss Madison
Concorde
Model number T-0001 K-5401-0 K-3989 2887.218.020 CST412MF.01 SM-1T106
Rough in 12" 12" 12" 12" 12" 12"
Flush type Dual Dual Dual Dual Dual Dual
Touchless
Trip lever
Button
GPF 1.0 / 1.6 0.8 / 1.28 1.1 / 1.6 0.92 / 1.28 0.9 / 1.6 0.8 / 1.28
WaterSense .
CalGreen
MaP N/A N/A 1000g 600g 800g N/A
ADA
Rim height Height without seat
16-1/2" 15-5/8" 16-1/2" 15" 16-1/4" 15-1/2"
Elongated
Round
Square
WSA Water surface area
N/A 7-15/16" x 5-5/8" 11-3/8" x 8" N/A 6" x 4-1/2" N/A
Water level Rim to surface
N/A N/A 5-3/8" N/A 8-1/8" N/A
Dimensions 28.5 x 14.5 x 27.5" 26.4 x 17.2 x 21.4" 35.5 x 25 x 23" 15 x 29.8 x 30" 27.5 x 14.2 x 31.2" 27 x 14.3 x 29.5"
Weight 119 lbs 110 lbs 70 lbs 70.1 lbs 110 lbs 89 lbs
Trap size N/A 1-15/16" 2-1/8" 2" 2-1/8" 2.75"
Flush valve 3" 2" 2" 2-1/2" 2"
Concealed trap
Skirted
One piece
Two piece
Intelligent
Floor mount .
Wall mounted
Colors White White White White, bone, linen Cotton, Colonial, Beige White
Seat
Soft close
Bidet
Supply
Rating 85% 84% 83% 82% 82% 82%

Dual flush vs single flush toilet

Toilets with a dual flush are often overlooked in favor of those with single flushing mechanisms. But is it right to do so? In terms of saving water, both are generally equal as most modern products average out at around the 1.28 gallon mark. However, the ability to choose a half or full flush depending on the type of waste you're handling could cause confusion, especially among guests. The last thing you want is people accidentally using a lighter flush for solids and leaving it in the bowl, leaving the room smelling and unhygienic for the next user. The same applies to using too much water for liquids and being wasteful.

When used the right way, in other words, partial for liquid, and full for solids, the advantages are clear to see. They can be economically and environmentally friendly, giving consumers full control over their water usage. Over the years, this can result in thousands of gallons being saved and hundreds of dollars.

List of in depth reviews

We've reviewed each of our picks below and given some reasoning on why we chose them. We pay attention to the specifications and look for specific areas of interest that may give them an edge over their competitors.

WoodBridge T-0001

The T-0001 contains some top class features that enable it to rank high on our list. Without a doubt, the overall theme and external design is one of its main selling points. The fact that it's one piece, and conceals the trapway gives it a few points in the aesthetics area for us. Then you've got the white color which is able to brighten up any bathroom.

To operate the flushing system, users must push the rectangular buttons located on top of the tank. Each one with a differing amount of water used. The light one uses a very conservative 1.0 gallons, and the stronger one uses a heavier, less eco friendly 1.6 gpf. However, putting them together to get the average, enables it to meet the Environmental Protection Agencies WaterSense criteria. This can save users up to twenty percent compared with conventional models.

The height of the bowl and seat is taller than seventeen inches, meaning this is categorized as comfort height, and makes sitting and standing easier on the joints and muscles. Some people prefer standard height, but for senior citizens, or tall people, we recommend going this route.

The good thing about this unit is that it's the full package. What happens quite often is consumers have to but the smaller fixtures like the seat separate. That's not the case here, with a pre installed quiet close seat, bolts, wax ring, and instructions all included within the price tag.

This is one of our favorite options using this mechanism. It doesn't use much water, it achieves a strong siphonic flush, and is built for user comfort through its elongated shape bowl which is taller than average.

KOHLER Veil K-5401-0

The Veil is a smart toilet that has all the features needed to modernize your bathroom. Externally, it has smooth and clean design, made from vitreous china, and concealing the inner hardware from view. There isn't many similarities between this style and a standard toilets. It's certainly unique in many ways.

The gravity fed flush consumes either 0.8 gallons or 1.28 gallons, ensuring it meets EPA standards, and unlike our other choices, it's got a tankless design, taking water directly from the supply line instead of through the valve.

If you're someone hat tends to get up in the middle of the night often, you will appreciate the built in LED light night that illuminates the bowl and lessens the need of turning on the main lights, which isn't pleasent if you're still half asleep.

You can say goodbye to using toilet paper too. With the use of it's integrated spray and dryer, it becomes obsolete. The integrated bidet spray is far more efffective at cleaning and has several different spray settingsthat enable users to change the shape, position, water pressure, and temperature. The dryer mechanism will take care of the rest. All of this can be controlled via a remote control.

You can also heat up the seat as a luxury. Getting on a warm seat is far more relaxing than a cold one after all. The seat itself is motion activated. This means it will automatically sense when you are coming or going and open and close accordingly.

The old ways of stopping bad odors rising through a large water surface area are becoming less necessary too. For this has a deodorization system that filters out the bad air when required, leaving things fresh and more pleasent for the next user.

The product dimensions are 26.4 by 17.2 by 21.4 inches and weight is 110 pounds.

Despite its numerous innovations that improve convenience, leave things hygienic, and just make life easier for the user, there is one major problem. It's not cheap. In fact, in comparison with the others we've chosen in this article, it's very expensive. That's the price you pay for all the new technological advancements included. But if you can afford it, there really aren't many flaws. We can't help but feel some of the specs are overkill.

KOHLER Highline K-3989

This unit from the Highline range of Kohler includes the K-4458 tank and K-4199 bowl. Instead of making use of buttons, it has a left hand trip lever on its tank which allows the user to choose between a partial 1.1 or full 1.6 GPF rate.

By averaging out these two water powers, it is able to meet WaterSense criteria and will be labelled as such. Every time someone uses the low flow, 1.1 gpf flush over the 1.6 one, you stand to save up to thirty percent, which can mean as much as four thousand gallons of water every year. The more people living in your household, the bigger the savings can be.

Looking at overall performance, Kohler describe it as being Class five. This is the highest marks you can get and put simply, it means that it's unlikely to get clogged up. On the Maximum Performance scale, it achieves an impressive 1000 grams score too.

The bowl is elongated in shape, ensuring bigger and taller people get the extra space they require, and it's also ADA height, making it taller for better accessibility for the average person. However, unlike the T-0001, this model doesn't have skirting around the sides. We're not a fan of this as we think skirting improves the design a lot.

The seat will need to be bought separately, with the K-4636-0 Cachet, C3-230, and K-5588-0 all being compatible options.

Its dimensions are 35.5 by 25 by 23 inches and it weighs 70 pounds. It fits a standard 12 inch rough in size, and has a 2-1/8 inch, fully glazed trapway. Users will also appreciate the rim distance from the water surface (5-3/8") This will help prevent splashing.

Looking at all the features and specifications in one place, we can see that this is an option for people working with a smaller budget. It's not the most advanced product on the market, but it's made by a reputable company and will get the job done in your average residential setting.

American Standard H2Option 2887.218.020

The 2887.218.020 has a minimalistic, two piece design where the trapway is exposed. It has buttons on the top of the tank, similar to the WoodBridge model, and it's coated in the American Standard EverClean anti-microbial surface which helps it stay cleaner for longer by stopping odor causing bacteria from clinging to the bowl. It's also available in white, bone, and linen to meet the needs of varying bathroom themes.

Unlike the two above however, this has a standard height bowl. There are arguments for and against using this over a right height option, but it always comes down to the type of person using it and what their preferences are. Users can change this model to the 2886.218.020 if they prefer the ADA compliant, higher rim.

The trapway isn't very large, measuring 2 inches. However, there are bigger options that can handle a greater quantity of waste through them. Read more about them here.

If you're after a higher level of water efficiency, this could be the product you've been searching for. It features a 0.92 / 1.28 double flush, allowing it to meet EPA, CALGreen, and CEC criteria. The actual mechanism it runs on is a siphon jet bowl technology with the addition of a powerwash rim to get to, and rinse the harder to reach areas. So, if it's environmentally friendly you're aiming for, this could be a good match for your washroom.

The MaP score given is 600 grams, and it also falls into Maximum Performance Premium category, which tells users it can handle waste well, and do so with less water.

However, readers will need to purchase the seat, wax ring, and supply line separately. So while it may seem reasonably cheap on paper, you'll want to budget for these extras if you don't already have them.

TOTO Aquia CST412MF.01

If you've ever wondered about the capabilities of the different manufacturers out there, we recommend TOTO. They are known to produce reliable products that are durable. And that's not just reflected in consumer feedback either. You'll come across many plumbing professionals that have had similar experiences using them. In this review, we look at their Aquia model and its functionality.

First things first, the bowl. This is skirted, which is necessary if you want that smooth, contemporary style. It ensures washing the exterior becomes less arduous. It's also universal height, making the rim height slightly taller in order to meet Americans With Disabilities standards for accessible design.

To operate the flushing mechanism, there is a user friendly button on top of the tank. Once pressed, a total of either 1.6 GPF (6.0 LPF) or 0.9 GPF (3.4LPF) will be sent through the valve to remove waste through the outlet. This is a low water consumption model which meets sustainable minds, WaterSense, and CALGreen criteria.

It doesn't have the largest of water surface areas, with measurements of 6 by 4-1/2 inches. Which is unfortunate because it helps keep odors down. However, the water line is much lower, measuring 8-1/8 inches from the rim. This is a bigger distance then average and one which will prevent water splashing up and hitting you.

Overall, we think this could be a great replacement for your home. It's made by a well known company, and there is plenty of customer feedback to get further details about its pros and cons. It's eco-friendly, and scores high on the MAP scale (800g).

Swiss Madison Concorde SM-1T106

The Concorde has a beautiful one piece construction that can improve the overall appeal of the bathroom. The skirted trapway plays an important role in this, smoothing over any edges and joining the bowl seamlessly. This also makes cleaning the bowl easier as there is no cracks for the germs and dust to hide.

The bowl is square / rectangular shaped, which isn't really built with user comfort in mind. However, it is glazed for the protection of the china and it does add a touch of elegance that would otherwise be missing.

Like the others, you get to operate two flush powers. The only difference in comparison to its competitors is that it's far more efficient. It still uses a low flow 0.8 GPF for the liquids, but this unit utilizes just 1.28 gallons for the solids. We look at this as a water efficient option for people who care about the environment and the impact of utility bills on their wallet. Readers can learn more about what they can save vs conventional model using our calculator.

The inclusion of a slow close toilet seat is a nice touch that can save consumers money. That's because manufacturers in this industry like to upsell them at checkout. If you're trying to be careful with how much you intend on spending, this is important. The seat itself has the soft closing hinges that make it impossible for it to be slammed shut. It also has a quick release feature that ensures removing it for cleaning purposes is simple.

If it's a modern style you're after coupled with solid performance and low water consumption, the SM-1T106 could be exactly what you've been searching for.

Other things to consider

Rough in - You will need to know what size installation you require. This will usually be one of the following: 10", 12", or 14". There are brand specific options like the UniFit that allow you to use a simple attachment to fit any of these three rough in sizes.

Performance - Stick with units that achieve a 500 grams score or more on the MaP scale. This demonstrates a products ability to move heavier amounts of waste.

Bowl shape - There isn't many limitations when it comes to how you design and layout your bathroom theme. Even in the smaller details like the bowl shape, you're presented with several choices. Elongated, round, and square are all shapes which you could potentially use depending on your requirements. Each one has their own attributes for specific situations. Round for small washrooms, elongated for user comfort, and square for aesthetics. What you choose comes down to user preference.

Glazing - Read the description of each product you're interested in. Make sure it has some kind of glazed coating of the ceramic material. This will help improve the effectiveness of the fushes rinsing capabilities, and stop germs and dirt building up in areas you don't want them.

Water spot - Two things to consider when looking at the water spot. The surface area, and how high the water line is. If you've got a surface area that's too small, you're going to end up with more stains and streaks as a result of waste missing its mark. However, if you go too large, you end up with the water line sitting very high in the bowl, too close to where you're seated. This will mean splashing becomes a problem. The idea is to get a nice balance between them both, and for that reason, we suggest getting a model that has a water line that is at minimum five and a half inches away from the rim. You can find some that meet this measurement by using our comparison tables in all our guides.

Brands - Other than the brand names we've already covered above, there are also several alternatives like Mansfield, Sterling, and Gerber. You can read our guides on each through our menu.

Customer reports - Look at the ratio of positive to negative comments on stores and shops online. See what's being said about it and try to get a feel of how pleased consumers are with that specific purchase. Sometimes you can learn important information about defects that will save you time and money.

Conclusion

Dual flushing toilets can be beneficial to any household. They can make a noticeable difference in the amount of water saved each year and lower your household bills over the products lifetime. The models we've chosen above meet a lot of the criteria we look for in our research. We have some that are efficient, others that have allow greater access for the disabled, and some that are high performance. Once you decide on buying a specific product, make sure you follow the tips outlined above and avoid the common buying mistakes that many consumers make.