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Low Flow and Ultra Low Flow Toilets - Need to Know

Reviewed By:
R. Dodge Woodson

In today’s environmentally conscious society, conservation has had an impact on just about everything --- including home improvement. Homeowners are building and remodeling their homes to conserve energy and save money; utilizing a slew of new products and methods to assist them in their endeavor. One such product is the advent of the low-flow toilet.

Low-flow and ultra low-flow toilets, mandated by the U.S. Department of Energy, have been a part of the home building process since the early 1990s.

Both low-flow and ultra low-flow toilets look just like regular toilets and measure the same size, however, they use only half the amount of water, averaging about 1.6 gallons per flush instead of the traditional 3.5 gallons per flush. This means less overall flushing power but more water conservation; prior to 1983, toilets were worse, using as much as five to seven gallons of water in a single flush.

The main difference between the low-flow and ultra low-flow toilets has less to do with cosmetic appeal and more to do with efficiency. In most cases, the tank still holds about 13 liters of water, but only six are flushed at a time. Additionally, some ultra low-flow toilets don’t have traditional flappers on them and offer the option of a half flush for liquid waste and a full flush for heavier waste.

Low-flow and ultra low-flow toilets both come in two main categories: gravity-fed and pressure-assisted. Gravity-fed is the same kind of design as a regular toilet with a valve-siphon piece in the place where the ball cock is normally found.

Pressure-assisted is noisier, but reduces water consumption over gravity-fed by up to 45%.

Both low-flow and ultra low-flow are more expensive to purchase than a regular toilet, however, as a long term investment, they make more sense because you will shave money off your water bill over time.

Since low-flow toilets first made their debut on the home improvement market, there have been numerous technological advances made to enhance convenience and performance. For example, many low-flow toilets now have larger drain passages, making them less likely to clog. Additionally, redesigned bowls and tanks have more efficient, decorative designs.

For the last decade low interest rates have spurred a dramatic rise in home building and home improvement in the United States making low-flow and ultra low-flow toilets the norm in most households and businesses across the country. Those who had homes built prior to the U.S. Dept. of Energy mandate have had to make the switch to the water conserving low-flow and ultra low-flow toilets as they’re the only type on the market. And not only low-flow toilets but many bathroom remodeling projects have added other low-flow plumbing fixtures, such as showerheads and faucet aerators. In most cases, the combination of low-flow products end up as cost-saving measures for the homeowner as well as saving a little piece of the environment.

Many low flow fixtures can be installed by the do-it-yourselfer, as they often come with an easy-to-understand set of instructions. However, if you have any doubts it’s best to have a professional plumber install your low-flow toilets.

Low-flow toilet conversion can be somewhat expensive but most homeowners see the benefit once they see the energy savings on their water bill. Over time, the purchase should show a return for the homeowner as they save money, well beyond the initial investment.

Installing low-flow and ultra low-flow toilets in your home is just one step in remodeling for energy efficiency. Many changes, including this one, are not usually too costly up front and can save you a great deal of money over time.

R. Dodge Woodson is a master plumber of over 30 years. He has written over 90 books dealing with many subjects, including plumbing.