Single Flush vs Dual Flush Toilets: Comparison and Guide 2022

We generally associate single flush with traditional toilets. While many modern toilets are also equipped the single flush technology, you will find a large portion of them to be dual flush toilets. This has given air to the single flush vs dual flush toilet debate.

So are single flush toilets actually a thing of the past? And with the new water conservation laws in action how profitable it is to use single flush toilets over dual flush toilets.

In this article, I have done an in-depth analysis of single flush vs dual flush toilets. The pros and cons of both types are listed along with a side-by-side comparison.

Single Flush Toilet

The most frequent form of toilet found in older homes and buildings is the single-flush toilet. They only have one flush mechanism, which means that all waste is flushed with the same quantity of water, sometimes as much as 5 gallons.

Because single-flush toilets are more widespread in homes and businesses, it is typically easier to acquire replacement components for them if something in the tank breaks, which can result in lower repair expenses. Furthermore, some users choose single-flush toilets for aesthetic reasons, preferring the lever which may be modified based on personal preference over the button.

However, single-flush toilets use substantially more water than their alternatives, making them more environmentally destructive and pricey on your water bill.

Dual Flush Toilets

A dual-flush toilet is a type of flush toilet that employs two buttons or a handle mechanism to flush various volumes of water at the same time. This mechanism’s goal is to minimize the amount of water utilized to flush various forms of trash. The design capitalizes on the fact that liquid waste uses less water to flush than solid trash.

Dual flush toilets operate differently from normal American-style toilets, providing the user a choice of flushes. It’s a water-saving interactive toilet design that has swiftly gained on in nations where water is scarce, such as Australia, and in locations where water supply and treatment systems are outdated or overburdened.

Dual-flush toilets consume significantly less water and are considered ecologically friendly. Using one can result in decreased water costs, which can save your family money over time. However, some customers believe they are more difficult to flush – the top-of-the-tank buttons might often take more energy to press than a lever, which can be challenging for handicapped or elderly people. Because they are less frequent, new parts may be more difficult to get, and repairs may be more expensive if something goes wrong.

Single Flush vs Dual Flush Toilets: Comparison

Now that you know the basic features of Single flush and dual flush toilets, let’s compare the characteristics side by side. The difference between them and the advantages and disadvantages of each type are mentioned in detail.


The major distinction between dual flush and single flush toilets is the flushing technique they employ.

Single flush toilets use siphoning action, a method that employs a siphoning tube, to evacuate waste. A high volume of water entering the toilet bowl when the toilet is flushed fills the siphon tube and pulls the waste and water down the drain. When air enters the tube, the siphoning action stops.

Dual-flush toilets, on the other hand, feature two flush mechanisms — typically, two buttons on the tank’s top rather than a lever. One button activates a flush that uses less water and is intended solely for liquid waste, while the other activates a flush intended for solid waste.

Water Consumption

Water usage is the most noticeable difference between dual and single flush toilets. Since single flush and dual flush toilets employ different flushing techniques, the water used in both cases also differs.

Single flush toilets are known for a powerful flush using a heavy volume of water; which is why they are not considered an eco-friendly option altogether. The dual-flush toilet uses substantially less water, which reduces operating costs and is healthier for the environment.

While most dual-flush toilets are water-saving, some may not save as much as intended. Some dual-flush toilets in the United States have flushes of 1.6 and 1.28 US gallons (6.1 and 4.8 l), respectively, which do not meet WaterSense label standards and hence cannot be categorized as high-efficiency toilets.

Indeed, having the option of selecting between two water consumption rates is connected with higher pricing than the typical single flush option. This may also have an impact on maintenance when it comes to servicing the flushing mechanism.

Installation and Repairs

Single-flush toilets are not something that come into fashion recently. They have been around for quite a long time. Thus it is typically easier to acquire replacement components for them if something in the tank breaks, which can result in lower repair expenses. Also, there are little to no chances of leaks which means no frequent repairs cost.

While dual flushing saves money in the long term, the initial purchase price is greater, and upgrading a toilet requires installation. Also since they are a new invention, you may face certain difficulties in finding new parts. This means that the cost of repairs will generally be high when compared to single flush toilets.

Single Flush vs Dual Flush Toilets: Pros and Cons

Pros and Cons of Single Flush Toilets

Single flush toilets are popular due to their ease of use and low cost. Most make use of widely distributed replacement components that are easy to get and relatively inexpensive to maintain. Furthermore, they frequently come with levers rather than buttons, which is a nice feature for the elderly as well as individuals with particular health issues affecting the hand and/or wrist.

The biggest minus point of single flush toilets is that they consume a huge volume of water. While it is quite essential for a crapper to have a powerful flush, a single flush mechanism is often regarded as a less efficient method.

However, there is a simple reasoning behind this. Single flush toilets are designed in such a way that you never have to face the issue of clogged toilets. It sends enough water down the pipes to leave the bowl sparkling clean and the user satisfied. But when dealing with liquid waste, the major issue is quite a likely misuse of water.

The good news is that the days of a single flush toilet using around 3.6 gallons of water per flush are long gone. The market now provides a variety of high-efficiency and ultra-high-efficiency single flush toilets. Although applied throughout usage, they have a minuscule water consumption rate starting at around 1.0 gpf.

Pros and Cons of Dual Flush Toilets

Dual flush toilets will save you water and money in the long run. In some locations, you may be eligible for a rebate if you use a dual flush, high-efficiency, or ultra-high efficiency toilet. This is likely to compensate for the high cost of dual flush toilets, which is a key drawback of this design.

A dual-flush toilet with a full flush at the US legal maximum of 1.6 US gallons (6.1 l) must have a reduced flush of 1.12 US gallons (4.2 l) or less to meet the WaterSense standard of 1.28 US gallons (4.8 l) on average, according to the WaterSense averaging rule over two reduced flushes and one full flush. A typical WaterSense combination for dual-flush toilets is a reduced flush of 1.1 US gallons (4.2 l) and a full flush of 1.6 US gallons.

Dual flush mechanisms are also more likely than standard siphons to develop leaks; dual flush toilets are likely to waste more water than they save owing to a combination of leaks and uncertainty over which button to press.

Finally, the most popular trigger option is a dual button, which may be inconvenient for some demographics, such as those with impairments and, according to some of my customers, people who want to keep their nails long — a flush button, they say, is a prescription for a broken nail. Fortunately, versions that combine the straightforward, simple lever design with dual-flush capability have hit the market.

Single vs Dual Flush Toilets: FAQs

How does a Dual Flush toilet work?

The dual-flush toilet, which evolved from the classic Australian flush toilet, differs from siphon-flush toilets in that it depends on gravity to remove waste from the toilet. Because there is no siphoning, the toilet uses less water to run. As a result, the waterline is significantly lower than in siphon-flush toilets.

Instead of a single-flush button, the toilet has two buttons on the cistern; one provides less water (e.g. 3 liters) and the other more (eg. 6 liters). It also has a bigger 10 cm trapway in the bowl, which allows water to exit faster and clear the bowl more efficiently.

There are also dual-flush toilets that employ a siphon valve rather than buttons to provide a 6L full flush and a 3L half-flush if the flush handle is held down or released immediately after flushing. When the lever is cranked halfway, the tipping bucket cistern may work in dual flush mode.

Do Dual Flush toilets use less water than single flush toilets?

The manner in which water is utilized to remove trash from the bowl has a significant impact on the amount of water required to complete the task. Dual flush toilets have a bigger trapway (the hole in the bowl) and a wash-down flushing system that forces waste down the drain.

Because there is no siphoning action, the system uses less water every flush, and the greater diameter trapway allows waste to easily escape the bowl. When combined with the savings from only using half-flushes for liquid waste, the dual flush toilet design may save up to 68 percent more water than a single flush toilet.

Are Single flush toilets easier to install?

Actually no. There is little to no difference between installing a single flush vs dual flush toilet. The installation process for both is quite similar and can be done without professional help too. Of course, you can take the help of a professional plumber to do it the easy way.

Final Verdict

Now you know the difference between the single flush and dual flush toilets. I have made sure to mention which model will suit your particular preferences and country needs.

Single flush toilets are still very much in demand even in this era of technological advancement. The reason is simple, most people still find traditional toilets to be more comfortable in comparison. But don’t let that stop you from picking a dual flush toilet for lesser water wastage.

It is not easy to come to a decision in the single flush vs dual flush toilets debate. Both toilets have their fair share of pros and drawbacks. Single flush sometimes excels in fields where dual flush lacks such as widespread availability and affordable price. Similarly, dual flush toilets lead the way when it comes to water conservation.

As I said before it is all up to a person’s preference. I have done my best to list both the pros and cons of single flush and dual flush toilets. It is up to you to decide which toilet you want to install in your restroom.Make sure you know who will be using the toilet before you make a purchase. And while you might be attracted by cheap options, remember that it may lead to health issues if you chose the wrong model.

Choosing the right toilet could prove to be a complex task given the number of factors that come into play. It is always better to have both models at your home, single flush and dual flush toilets, especially if you have a big family. So go ahead and choose the model that perfectly suits your requirements.

I hope the information given you helps you in some way. Please feel free to share your thoughts in the comment section below.

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