Dual flush toilets are a great option that comes with few downsides. By providing the user the choice between two flush options, dual flush toilets allow you to save overall water usage. For example, they only use about 0.8 gallons of water per flush for a partial flush (for liquid waste) and about 1.6 gallons of water for a full flush (for solid waste). Especially with the ability to use a partial flush when possible, you’ll see that compared to other types of toilets, dual flush toilets use about 4.5 gallons less than conventional single flush toilets do.
Let’s talk about a few key features to consider and recommendations for some dual flush toilet models:
- Dual Flushing Mechanism
- Dual Flush Button Explained
- Comparison Table
- 6 Dual Flush “Water Saving” Reviews
- How Dual Flushing Works
- Introduced to the Market
- EPA Rating
- Single Flush vs. Dual Flush
- Advantages of Dual Flush Toilets
- Choosing the Perfect Dual Flush Toilet
- Installing a Dual Flush Toilet
- Frequently Asked Questions
- Bottom Line
Dual Flushing Mechanism
All toilets with dual flush technology have an improved system for flushing, allowing them to achieve very powerful and effective flushes with minimal water usage. Additionally, there are two main flushing structures available:
The first option is a pressure-assisted flushing structure, which uses a mixture of water and highly pressurized air. These systems are often more expensive and louder, but also more powerful.
Gravity Flushing System
The second option is a gravity flush system, which are more common than the pressurized ones. Such systems use gravity with water weight to produce the pressure for each flush. Gravity flush systems are also much quieter and water-saving compared to pressure-assisted options.
Dual Flush Button Explained
In most cases, a dual flush toilet will have two buttons – a larger and a smaller one.
For liquid waste, you should 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.
6 Dual Flush “Water Saving” Reviews
#1. TOTO Aquia IV Dual Flush Toilet
TOTO designed the Aquia white porcelain model in a timeless classic style that will fit any bathroom interior design. Moreover, its compact size means it can be placed in a corner of the bathroom if you have limited space.
The toilet is designed with a dual flush button that can be pushed halfway for a partial flush or pressed all the way for a regular flush. Additionally, the toilet has been designed to have a textured finish that helps shed water and is much more resistant to waste build-up, scratches, and stains.
The Toto Aquia comes with a very clear step-by-step instruction booklet that makes it easy to understand how to install the toilet and how to operate or perform small fixes as needed. Also, it is a bit taller than the standard TOTO toilet models, hence it will be more suitable for taller individuals as well as elderly family members.
You may be interested in our full review of the TOTO Aquia IV
#2. TOTO Ultramax Dual Flush
The TOTO Ultramax Dual Flush offers maximum flush efficiency. In particular, the trap way has been computer-designed and tested for super-efficient and clog-free use throughout the years. Designed for both households and RVs, this toilet is equipped to handle up to 3.8 gallons per flush without the water backing up. Plus, this model is sold in 5 different finishes including the high-end CEFIONTECT ceramic glaze.
Further, the single-piece design will eliminate the need for frequent cleaning especially between the bowl and the tank. Customers have reported this model to work flawlessly with a strong flush and bearable noise level.
#3. TOTO Ultramax One Piece Toilet
The TOTO Eco UltraMax has low water consumption at just 1.28 gallons of water per full flush. The toilet is glazed in a patented SanaGloss finish that prevents mold, mildew, fungus, and debris from sticking to its porous porcelain and ceramic surface.
The gloss works great because it seals the china with an ionized barrier that creates a super-smooth surface that is easy to clean with each flush. Moreover, the catalyzed ion particles even repel debris and rust.
This model’s soft closing seat has a comfortable ergonomic design and molded bumpers as well as a polypropylene finish to prevent the common and annoying toilet seat bang.
Finally, if needed, customers can order a separate toilet seat they can later use to replace the old one. All TOTO toilet seats are made to fit all models regardless of whether the model is regular or elongated, so finding a replacement shouldn’t be an issue.
You may be interested in our full reviews of TOTO toilets
#4. American Standard H2Option Dual Flush
In our opinion, this American Standard model is the best dual flush toilet. It comes in three colors: standard white, linen, and bone. This product weighs only about 68.8 pounds and has a round bowl. Due to its shape, it is a bit less comfortable but still very practical. Round models are often a few inches smaller and more compact than elongated models, so this toilet will fit in any space, even smaller bathrooms.
Further, keeping this toilet clean and bacteria-free is a piece of cake with the EverClean surface. The dual flush mechanism offers 0.9 GPF with the light flush and 1.28 with the full flush and it features a siphon jet bowl with PowerWash to provide optimal performance. Additionally, American Standard provides a five-year limited warranty on the mechanical parts as well as a lifetime limited warranty for the chinaware.
You can find the right height version of this toilet online, but the standard model is 15 inches high and not as comfortable for sitting. The toilet itself is effective and powerful. It is also very affordable and makes a perfect choice if you want to save some space.
Check our in-depth review of the American Standard H2Option
#5. KOHLER Wellworth Dual Flush
Because of its round shape, the Kohler Wellworth is not the top choice in terms of comfort. However, if you have a small bathroom, it may be the best dual-flush toilet for you. This toilet offers you the choice of 1.6 and 1.1 gallons per flush, saving at least 4000 gallons per year and reducing water bills. Further, it has a classic 12-inch rough-in to simplify installation, and comes with a standard one-year warranty.
This model is a floor-mounted round toilet. With the Class 5 flushing technology, it offers magnificent power and water flow rate. It has a very sleek, modern, and stylish look. This toilet is available in four different colors, biscuit, white, almond, and black, so it fits any type of bathroom. It is made out of china and is very durable compared to ceramic models. Even though it is durable, it is definitely not the heaviest toilet out there, which helps with installation as well.
Please read our full review of the Kohler Wellworth toilet.
#6. TOTO Drake Dual Flush Toilet
Due to the 17-inch universal height elongated bowl, the Toto Drake is very comfortable and a perfect choice for older people with movement issues. Even though it is made of ceramic, it is just as durable as most modern toilets. Due to the CEFIONTECT glaze, no bacteria or particles will stay in the bowl. In fact, this layer of very smooth glaze will keep your bowl clean for a long period of time.
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 dual flush system, you will save approximately 3500 gallons of water per year without compromising on performance.
Don’t forget to check out the full review of the TOTO Drake here.
How Dual Flushing Works
To understand how dual flush 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 dual flush 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. To understand in more detail, check out the video below.
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 dual flush toilet leads to significant water savings over time. And while dual flush toilets may seem like new technology, they were actually patented a long time ago.
The first dual flush 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. 16 years later, the system was mentioned in the book Design For the Real World by Victor Papanek. 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.
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 Water Sense 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, a dual flush toilet gives 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.
Advantages of Dual Flush Toilets
One of the main advantages of dual flush toilets is that 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. Especially if you have multiple family members using the dual flush toilet, the water and money savings will really add up over time.
Another advantage of dual flush toilets 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 a dual flush toilet, meaning overall performance isn’t compromised even while you save on water.
Choosing the Perfect Dual Flush Toilet
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, dual flush toilets use the least amount of water when compared to any other type of toilet. However, while all dual flush models are great water efficient choices, how do you choose the perfect dual flush toilet for you?
Here are 4 factors to consider:
1. Seat Height
The height of your toilet plays a very significant role when it comes to comfort and convenience. Therefore, regardless of the type or design of your toilet, always consider the height. Most standard toilets are about 15 inches away from the ground. However, there are many comfort-height toilets out there to choose from, which are typically ADA-compliant and around 18 inches in height. Such design makes sitting on them feel like sitting on the average chair. The increased height and comfort makes these toilets a great choice for people with movement disabilities.
2. Durability and Warranty
Most units that include the dual flush system are well-known for their durability. Still, to ensure the quality of their products, most companies offer at least a 1-year warranty. It isn’t unusual for some companies to even offer an extended warranty, depending on the brand of your toilet. In that period, buyers can return the product back to the company if it is faulty. If that happens, you most likely will be given a fresh replacement or free repair, depending on the issue. Look for a durable model when investing in a new toilet, and if you’re very concerned about needing repairs, look for options with longer warranties as well.
Another thing to keep in mind while making a purchasing decision is noise. If you live with elderly people or kids, noisy toilets can make sleeping difficult. Especially if you have a baby, loud toilets can be a nightmare. Quieter toilets usually have gravity flushes, which minimize the sound of each flush. On the other hand, air-pressurized models are often way louder. If you’re in a noise sensitive environment, keep the type of flush in mind before selecting your new toilet.
4. Size and Shape
In terms of shape, there are two common types: elongated toilets and round ones. The elongated models are well-known for the comfort they provide. Their shape provides a better sitting experience than the round ones, although they do take up more space. In comparison, round toilets are normally about 5 inches smaller and are a better option for kids. Finally, a third option particularly if you have less space would be a wall-mounted toilet, which you can install easily in small bathrooms to maximize space.
Installing a Dual Flush Toilet
Installing a dual flush toilet 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:
- First, remove the old toilet from its current place. You can use a knife or scraper to remove the old wax ring.
- Then, put the closet bolts from the new product over the flange.
- Now, using a masonry drill bit, drill through the floor over the screw-hole marks carefully.
- After that, screw both mounting blocks into the floor.
- Put the new toilet in its place and make sure it fits perfectly over the blocks.
- Open the toilet tank and remove the flush valve.
- Install the tank on the bowl and carefully tighten the bolts.
- After connecting the water supply line, you have pretty much finished the process.
- Finally, flush the toilet a few times to make sure there is no leakage.
Be sure to check our full guide of how to install a toilet
Frequently Asked Questions
The best dual flush toilets can be confusing to maintain and sanitize. Plus, if you accidentally press the wrong side of the flush, you may need to flush again, thus defeating the purpose of dual flush toilets—to save water. Moreover, since dual flushing toilets have a separate flushing mechanism for liquid and solid waste, be prepared to change the flushing system completely even if the problem of faulty flush lies only in one small part breaking. While the dual flush mechanism has two buttons that can be pressed, their inside mechanisms are connected with one another, so you can’t repair one type of flush without needing to fix the other as well.
Absolutely. Compared to standard models, dual flush toilets save up to 67% more water, which can drastically decrease your water bills in the long term.
The minimum amount of water for a partial flush is usually around 0.8 gallons per flush. The maximum amount (full flush) is mostly between 1.28 and 1.6 gallons per flush. The models with 1.6 are usually more powerful than those with 1.28, although the 1.28 gallons per flush options minimize water consumption.
Various factors such as a faulty flapper or seal can cause the toilet to keep running. One factor that is often the cause is that the rubber piece might have misaligned. However, these issues are completely normal as the years go by, and are usually easy to resolve either on your own or with the help of a professional.
It can be rather difficult to find the best dual flush toilet online without some knowledge. Therefore, we hope our buying guide and overall recommendations help out before you make your purchase! Ultimately, the K-5401-PA-0 Veil is our top pick if you want the benefit of the luxury features it has to offer. Alternatively, consider one of the other models from our list if you’re looking for a more affordable option.