Single Flush vs Dual Flush Toilets

Dual flush toilets come with a flushing system that allows you to choose between a full and half flush resulting in water usage while single flush toilets come one option of a full flush resulting to more water per flush.
While single flush are more common and cheaper double flush closest are modern, rare and pricier.
Read on for a more detailed comparison.

Single Flush vs Dual Flush: Comparison Table

Below is a table highlighting how double flushes compare with single flush closets

 Single Flush ToiletsDual Flush Toilets
AvailabilityCommonNot so common
TechnologyOld technologyNew technology
Eco-friendlinessNot very eco-friendly. Uses much waterEco-friendly as it saves on water
OperationFoolproof/ Easy for almost everyone to useRelatively challenging for some people
MaintenanceRelatively lowRelatively high
Ideal forPublic toilets and ones that are not frequently usedPrivate toilets and homes and where the toilet is used frequently
Flush button/handle actionSingleDouble

The Differences

Flush handle/button (s)

The single flush toilet system provides only one flushing option, with a single flush emptying the tank’s contents.

Flush buttons- Single vs dual flush toilet
Single and double flush buttons

Dual flush toilets, on the other hand, provide two options: a half-flush for liquid waste and a full flush for solid waste. The flushing mechanism is activated by pressing one of two buttons or flushing with a handle.


A dual flush toilet flushes with two different volumes of water, whereas a single flush toilet can only flush with one volume of water regardless of whether it is flushing liquids or solids. A dual flush toilet, for example, will be rated as 1/1.6 GPF, whereas a single flush toilet will be rated as 1.28 GPF. This means that a dual flush toilet can use either one or two gallons of water per flush, whereas a single flush toilet can only use one gallon per flush.

Thus, dual flush toilets are considered more eco-friendly than single flush toilets because they use less water in flushing.

Mode of action

 Dual flush toilets use gravity to empty water from the tank  flush waste from the toilet bowl. A dual flush toilet uses less water than a single flush toilet because it has a greater trapway, gravity and push-down flushing system.

Most old Single Flush toilets on the other hand use a siphoning system to draw water from the cistern to flush waste down the drain.  This action requires a large volume of water to be effective.

Some modern single flush models have employed the gravity assist flush mechanism though, similar to the dual flush toilet one.

Flushing Mechanism

Most old single flush toilets and some new ones use a float ball fill valve but most modern ones use float cup fill valves, just like dual flush toilets.

In the cistern of a single flush toilet, there is a long arm which is attached to the flushing handle. A chain is then attached to the arm and the toilet flapper. When you flush the toilet, the lift chain lifts the flapper away from the flush valve opening, allowing water to flow down into the bowl.After releasing the handle the chain relaxes and the flapper falls back to position and seals off the flush valve.

Single flush system
Inside a single flash toilet

Counterwise, inside a dual flush toilet cistern, a large valve controls the amount of water that flows down to the bowl based on the button you pressed. When the toilet is not in use, the dual flush valve is mounted on top of the flush valve opening and has a rubber seal that prevents water from constantly running into the bowl.

Dual flush system picture
Dual flush system


The duo’s maintenance differs due to their modes of action. Dual flush systems necessitated more maintenance than single flush systems.

Because dual flush toilets have two flushing mechanisms, they are more difficult to maintain than traditional toilets. This can lead to more expensive repairs in the future.

Because the lower flush option uses less water, dual flush toilets require more cleaning. The water not only aids in the flushing process, but it also aids in the cleanliness of the toilet. Thus, less water means less rinsing of the bowl’s interior, which may necessitate more frequent manual cleaning of the toilet.

Single flush toilets are much-liked for their simplicity and affordability. Most use widely spread spare parts that are easy to get and are relatively cheap to maintain. Besides, they often come with levers rather than buttons, which is a welcome feature for elderly people as well as those with certain health impairments affecting the hand and/or the wrist.


Toilets with two flushes are usually more expensive than single flush toilets. This is due to the fact that their designs are more advanced than those of their competitors.

They rely on complex mechanisms for efficiency and water conservation, and as a result, they are costly.

Ease of operation

Single flush toilets are much easier to use than dual flush toilets. This is due to their simple design and use of handle mechanisms for flushing that are easier to use.

Dual flush toilets, on the other hand, can be difficult to use because they come in a variety of designs and are located in various locations within the cistern, which can be confusing.

Flushing in dual flush toilets can also be difficult for the elderly, people with disabilities, and children because the buttons are sometimes difficult to press. People with long nails also have difficulty pressing the buttons.

In short, the simple design of single flush toilets makes them easier to operate than their counterparts dual flush toilets.


Single flush toilets are generally considered to be more beautiful than dual flush toilets because of their handle designs. Most single flush toilet handles are well crafted and beautiful and can be changed.

The dual flush toilet flush buttons, on the other hand, aren’t considered appealing by most people. An exception is in the case of dual flush toilets that use trip lever handles.


Outward design

Exclusive of the flush buttons or levers in any case,the outward appearance of both toilets is the same. It is hard to distinguish between the two without seeing the flush buttons or handles or opening the cistern lid.

Fill valve

Unlike older designs that used the ballcocks Modern single flush toilet designs employ the use of float cup fill valves and other modern fill valve designs just as used in dual flush toilets.

Flush mechanism

While we are used to most dual flush toilets using two buttons for flushing, some dual flush toilet use handle for flushing, almost similar to the ones used in single flush button except that in the case of dual flush toilets, the handle can be moved up or down, either ways flushing different amounts of water.


Both can be eco-friendly options. Both can be WaterSense-labeled, which will allow you to save significant water each year. A Dual Flush toilet allows you to have a half-flush for liquid waste. A half-flush can be as low as 0.8 to 0.9% GPF.

Similarly, recent single flush toilet designs are made to be eco friendly as they use a reasonably small amount of water for flushing as in the full flush option in dual flush toilets.

Single flush toilet can also be modified to use less water by inserting some objects to take up the space of water and thus when you flush only a controlled amount of water gets into the bowl.


Another similarity between single flush and dual flush toilets is that either of both can easily be transformed or modified into the other. That is, you can easily transform a single flush toilet into a dual flush toilet and vice versa, using the correspondent conversion kits.


Both toilets also experience some similar functionality problems in their basic components. For example leaking fill valves, clogging of parts, deterioration of seals among other problems

 Which is Better, Single or Dual Flush Toilets?

In the previous sections, there seems to be some kind of balance with the two toilet systems not outweighing each other because each one seems to have some certain advantages over the other, regardless of their disadvantages.

Thus, before coming to a final conclusion upon which toilet is better than the other or is the best, there are several factors that you should consider because the definition “best” differs from one person to another. This is based on suitability, preference and necessity.

Some of the factors include:


In public toilets, single flush toilets are the best and are preferred for the fact that they use a lot of water in flushing. What is considered as a disadvantage now comes out as an advantage.

Because public toilets are used by many people, they might tend to be clogged due to a lot of solid waste being passed through. This is where single flush toilets come in handy as they use much water which effectively drains out solid waste.

A dual flush toilet wouldn’t be suitable for public toilets because of it’s same advantages which is using less water to flush waste as it would end up clogging up fast under the pressure of public use.

Regularity of use

While choosing the suitable toilet you should look at the regularity of use.

Dual flush toilets are suitable in places where the toilet will be used more often. This is because of the problem stated earlier which is, their disadvantage lies in their advantage of using less water in flushing. After flushing, the small amount of water does not effectively carry away all the waste through the drain.

If the toilet isn’t used for a longer while, the waste might get stuck there but in a place where the toilet is used often this is minimized by the multiple flushes in a day.

Single flush toilets on the other hand are effective in places where the toilet isn’t used more often because a single flush is almost always effective all the time.

Another reason based on regularity of use is the factors of saving water. A dual flush toilet can cost you more than a single flush toilet in terms of water usage, based on the usage and number of times you flush.

If a toilet isn’t used more often, a single flush toilet could suit the place as it is suitable and could do better than a dual flush toilet in the same place.

Counterwise a dual toilet is good in a toilet that is used regularly as it now helps you minimize excess water usage

Intended users

Another factor you should consider because choosing the best toilet for you is the people who will be using it.

As explained earlier in the article, dual flush toilet flushing buttons are sometimes challenging to use by the elderly and people with special needs.

Single flush flushing mechanisms are easier to operate because you only have to turn a handle.

However, some dual flush toilets have incorporated the use of flush handles but still aren’t easier to operate as the single flush ones.

Maintenance and availability of parts

Something else that you should consider when determining the best toilet system to install is the general maintenance requirement of the toilet in the aspects of cleaning and making repairs.

You should choose a toilet system that doesn’t demand a lot of maintenance and one whose parts are readily available to find and easy to fix .

As you can see, deciding which toilet is the best is challenging. There are numerous outstanding Single flush and Dual flush toilets that function well and are efficient.

In as much as each toilet system seems to have some advantages over the other and having some disadvantages too, dual flush toilets seem to outweigh single flush toilets in several aspects and are more preferable and popular among the population.

Single flush toilets are popular due to their ease of use and low cost. The majority rely on commonly available spare parts that are simple to get and maintain. Furthermore, they frequently use levers rather than buttons, which is a useful feature for the elderly and those with particular health issues affecting the hand and/or wrist.

There are certain trade-offs between a dual flush toilet and a single flush toilet, as you can see. Both can be environmentally friendly solutions. Both can be WaterSense-certified, allowing you to save a large amount of water each year.

In conclusion, the answer to the best toilet is not really straightforward. It is only based on the conditional factors explained previously in the article, that you can come up with a personal answer suitable to your preference.

Further Reading:

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