Single vs. Dual Flush | Comparison Guide 2024

Flushing a toilet is an everyday occurrence, but not everyone knows the ins and outs of this basic bathroom fixture. There are two main types of toilets on the market: single flush and dual flush. When buying a toilet, you’ll be faced with many models that offer one or the other.

While it may seem like a random decision, the type of flushing style you choose can make a huge difference in your home’s water bills and maintenance.

Take a look at our basic guide to figure out what type of flushing mechanism best suits your needs.

What are Single Flush Toilets?

A single flush toilet has one button or lever that releases all the water in the tank at once. This means that all of the waste is flushed down with the same amount of water regardless of its size or consistency. Over time, these types of toilets can be more expensive than other options because they require more water per flush.

Some models even come with an anti-jam feature that prevents clogs from forming in the pipes by allowing only small amounts of waste into the bowl at one time; if more water is needed, you just simply press the lever again.

What are Dual Flush Toilets?

A dual flush toilet is a toilet that uses two different amounts of water depending on the amount of solid waste being flushed. The two most common types of dual flush toilets include:

Two-Button Push System

This type of system has one button for the larger flush and another button for the smaller.

Single Lever With Two Levels

If you need a larger flush, push the lever fully down. For a smaller load, the lever only needs to go halfway.

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 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.

Comparisons of Single Flush vs. Dual Flush

Price Tag Winner

Dual flush toilets tend to cost more upfront but will save you more money down the road through your water bills. A dual flush toilet gives you the ability to drastically cut down on gallons per flush by choosing water usage based on your waste load amount. Some dual flush toilets have relatively lower water consumption even for their greatest water usage option.

For example, a dual flush toilet with a .8/1.28 gallons per flush will save you money regardless of the flush size compared to a single flush toilet that always uses 1.6 gallons per flush. 

Maintenance Winner

Single flush toilets require fewer parts than dual flush toilets thus making them easier to fix in case of breakage. Replacement parts for dual flush toilets tend to be more expensive than their single flush counterparts.

Investing in a quality brand will reduce the likelihood of breakage, making maintenance costs far and few. Additionally, keep in mind that the cost savings on water usage in dual flush toilets can also offset the occasional need for replacement parts. However, if you’re looking purely at maintenance costs with no other considerations, you’ll find single flush toilets win this round. 

Environmental Winner

It’s no surprise dual flush toilets are more environmentally friendly than single flush toilets. The option to use less water per flush can make a huge difference. In fact, WaterSense toilets, which are certified by the EPA, can reduce your water usage by 20 to 60 percent.

There are plenty of eco-friendly toilets that are single flush too that offer 1.28 gallons per flush or less. However, with the dual flush toilet, you have the option to slightly increase the water usage for loads that may be difficult to flush. 

Style Winner

Toilet styles are all about preference. In terms of functionality, both buttons and levers work reliably well. Dual and single flush toilets both come in a variety of designs that can even be personalized through different finishes and colors.

If you’re looking for an ADA-compliant toilet, it is important to pay attention to the toilet’s handle accessibility. ADA-compliant toilets cannot have their flush handles higher than 44” and cannot require more than five pounds of force to flush the toilet. Flushing handles need to be easily reached, with no uncomfortable maneuvering or straining of the body.

Luckily, both single and dual flush toilets have ADA-compliant models that will fit your needs. The only thing you need to decide is how you prefer your flushing handle to be designed.

FAQ’s

Our Opinion

When it comes to toilets, there are a lot of terms and phrases that are thrown around. Ultimately it comes down to environmental and financial benefits. Ask yourself what are the main things you are looking for in your new toilet. Is it cost, flushing efficiency, or design? This question will help narrow down what to look for in your search.

If you’re able to see your toilet as a long-term piece, consider investing in a dual flush mechanism and reap the benefits of monthly savings. In addition to being stylish, these models are comfortable and energy efficient, making them an all-around great investment.