Dual-Flush Toilets: Answers to Your Frequently Asked Questions


The great trend in plumbing these days is water efficiency; plumbers and homeowners alike are attempting to reduce water waste wherever possible, without sacrificing the effectiveness of water-based products. In response to this trend, the dual-flush toilet has become a popular option in both public and private bathrooms. Regardless of how much you already know about this water-saving device, we’re hoping that our list of frequently asked questions, along with our answers to them, will prove educational in terms of the hardware and benefits associated with the dual-flush toilet.

What is the dual-flush toilet?

The dual-flush toilet is a toilet that allows the user to choose how powerful the flush is. Most dual-flush toilets have two options (hence the name): a lighter flush meant for smaller jobs (liquid waste) that typically uses 0.9 or 1.0 gallon of water per flush, and a heavier flush meant for larger jobs (solid waste) that uses 1.28 or 1.6 gallons per flush.

How are dual-flush toilets flushed?dual_flush_close_up

There are a few different dual-flush lever options on the market today. Some toilets have what appears to be a standard lever, which is raised for one flushing option and lowered for the other. More commonly, a button controls the flush. The button will be divided into two sections, usually labeled 1 and 2. Press 1 for liquid waste and 2 for solid waste. These buttons are more often than not located at the top of the toilet, but can be found on the right or left side as well on certain models.

What are the benefits of a dual-flush toilet?

Dual-flush toilets give you the option to choose how powerful a flush you need, every time you flush. Because of this option, dual-flush toilets also conserve water, an important feature when the toilet accounts for 45% of the average water bill. Whether you operate a home or a business, dual-flush toilets can drastically reduce your monthly water bill, putting more money in your pocket.

Should I choose a toilet that uses a maximum of 1.6 gallons per flush or 1.28 gallons per flush?

More is always better, right? Not in this case. Nationwide, the most a new toilet is allowed to flush by law is 1.6 gallons per flush (gpf); however, many states have even stricter regulations. California and Georgia, for example, limit water usage to 1.28 gallons per flush, and many more states are set to follow their lead. Check out this article from the National Conference of State Legislators for more information on state regulations regarding flushing, and don’t worry too much about the quality of your flush declining; with toilet technology improving every day, today’s 1.28 gpf toilets can clear what a 1.6 gpf toilet could clear two years ago. A dual-flush toilet that uses a maximum of 1.28 gpf is a smart choice that will last for years.

Can 0.9 gallons of water really flush the toilet?

Yes! In fact, TOTO makes a toilet that only uses 1 gallon per flush with no option to use more water. Toilet technology has improved and evolved so rapidly in the past five years that 0.9 gallon per flush can get most jobs done. However, dual-flush toilets always have the second, more powerful flushing option if the need arises.

What are the drawbacks of a dual-flush toilet?

Dual-flush toilets cost more than typical toilets, but this cost is usually countered by the water efficiency savings that occur throughout the life of the toilet. Dual-flush toilets are also not as prominent as typical toilets, meaning design options are limited. Many brands will have one or two dual-flush toilets, as opposed to 20-30 regular flush toilets.

Are dual-flush toilets available in ADA/Universal Height?

Yes. There are many ADA Height dual-flush toilets on the market, including some from TOTO and American Standard.


Can dual-flush toilets be used in a commercial or business setting?

Yes, there are several dual-flush toilets that are intended for commercial use. See some here.

Are there any luxury dual-flush toilets on the market?

Yes. The TOTO Neorest collection, for example, includes a toilet with dual-flush technology.

Do dual-flush toilets include toilet seats?

It depends on the brand. Some, like the Kohler Saile Elongated 1 Piece Toilet, do, while others, like the American Standard H2Option Elongated 2 Piece Toilet, do not.

Anything else I should know?

Dual-flush toilets are a great option for the entire family or office, and an easy way to save money every month. No matter who uses the toilet, they will have a pleasant time, every time.

Want to see more dual-flush toilet options? Check out SUPPLY.com’s entire collection!