IN “FLUSH WITH POWER,” AN EPISODE of Fox's surprisingly funny animated show “King of the Hill,” Hank Hill joins the zoning board to overturn a local ordinance prohibiting the use of high-flow toilets. Inefficient, low-flow toilets, Hank argues, cause people to flush more, which, in turn, ends up wasting more water than old toilets.

The cartoon narrative is a parody of a real-life issue that is by now all too familiar to everyone in the home building industry. As a water conservation measure, Congress passed a law in 1992 requiring that, by 1994, all new residential toilets sold in the United States use no more than 1.6 gallons of water per flush. The subsequent consumer criticism that 1.6-gallons-per-flush toilets did not do a good job is well documented.

Water Saver

The spirit of low-consumption toilets—to save water—was admirable, but manufacturers' execution of the technology was less than stellar. “As a broad brush statement, I would agree that [early 1.6-gallon flushing technology] was not that successful,” says Frank Vullo, director of product development for Dallas-based Eljer Plumbingware. Some complaints, says Vullo, had nothing to do with the toilets. “People had no choice in whether they wanted to save or not save water,” he says, and that made them angry.

COMFORT FIT: Cimarron is engineered to handle the flushing demands of a commercial or residential setting, the manufacturer says. The toilet features a 3 ¼-inch flush valve combined with a direct-fed jet that maximizes water flow and allows for a 1.4-gallon flush setting option that saves up to 2,000 gallons of water per year. It has a 2 1/8-inch glazed trapway, an 11-by-8-inch water area, and a 16 ½-inch high bowl that makes it easier for users to sit and stand. Kohler. 800-456-4537. www.kohler.com.

COMFORT FIT: Cimarron is engineered to handle the flushing demands of a commercial or residential setting, the manufacturer says. The toilet features a 3 ¼-inch flush valve combined with a direct-fed jet that maximizes water flow and allows for a 1.4-gallon flush setting option that saves up to 2,000 gallons of water per year. It has a 2 1/8-inch glazed trapway, an 11-by-8-inch water area, and a 16 ½-inch high bowl that makes it easier for users to sit and stand. Kohler. 800-456-4537. www.kohler.com.

While that may be true, the general consensus is that early low-flow toilets were susceptible to clogging. James Walsh, product director for residential toilets for Piscataway, N.J.–based American Standard, says it basically came down to inefficient design.

“Early products had very small trap-ways with many bends and curves,” he says, “and the valve was more in tune with a 3.5-gallon toilet.”

Kathryn Streeby, marketing manager for sanitary products at Kohler, Wis.–based Kohler, says time—or lack of it—is partly to blame. “[Lawmakers] basically gave manufacturers less than two years to change their processes to design a product that uses about half of the water that it normally uses,” she says. The flushing process, Streeby explains, is somewhat like that of a straw. In this case, the straw (or trap) has to be small enough to create some force but large enough to prevent clogs. “First-generation products had smaller trapways, so there were clogging issues,” she says. “The industry had to play catch up.”

New Day

And catch up they did. Today, manufacturers spend millions in fluid mechanics research, use sophisticated software, and employ doctoral candidates to design toilets that use less water to remove more solid waste without clogging.

Some companies have addressed the problem with pressure-assist technology, but Vullo says that while the technology is outstanding, “it is hard to maintain, hard to fix, and very noisy.” Gravity-fed flushing is a better option, he says, but manufacturers had to perfect the technology to compete with pressure-assist products.

POWER FLUSH: The manufacturer claims that Champion has America's best flushing system. Instead of a standard flapper, the unit has a 3 ½-inch, one-piece flush tower that is short and wide so itstops the leaking, corrosion, and handle jiggling associated with the traditional flapper. It also has a 2 3/8 trap that is fully glazed with no choke points, which virtually eliminates clogging, the company says. It comes in white, bone, and linen. American Standard. 732-980-3000. www.americanstandard-us.com.

POWER FLUSH: The manufacturer claims that Champion has America's best flushing system. Instead of a standard flapper, the unit has a 3 ½-inch, one-piece flush tower that is short and wide so itstops the leaking, corrosion, and handle jiggling associated with the traditional flapper. It also has a 2 3/8 trap that is fully glazed with no choke points, which virtually eliminates clogging, the company says. It comes in white, bone, and linen. American Standard. 732-980-3000. www.americanstandard-us.com.

The industry says that it has made the technology better. American Standard removed the bends in the traps, glazed them, and increased their size to 2 3/8 inches. Kohler uses a 3 ¼-inch flush valve and a 2 1/8-inch glazed trap in its Cimarron product, and Eljer uses a 3-inch valve and a 2-inch trap in its Titan. The manufacturers claim that these new gravity-fed systems offer exceptional flushing power, quiet performance, and less clogging.

So, what's coming down the pike? In 1999, a Michigan Republican congressman sponsored a bill to repeal the 1994 federal law requiring low-flow toilets; the bill died, and Vullo says the topic of repealing the law is not even being discussed today. “The law will never be repealed,” Streeby says. “We think the water consumption will go even lower.”