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Research Center Flushes Low-Flow Toilets

Nov. 1, 1999
2 min read
In response to a request from manufacturers of low-flow toilets, the NAHB Research Center is undertaking an industry survey of water closet satisfaction. The survey, which began in June 1999, is an effort to measure consumer opinions about 1.6-gallon toilets that are now mandatory for new construction or remodeling in the United States. In the first month, the survey generated more than 1,000 responses from builders, property managers and homeowners.

According to respondents, several major problems have been flushed out of the surveys completed thus far:

  • Multiple flushes are needed to clear the bowls of low-flow toilets, therefore possibly negating any intended water savings with the use of 1.6 gallons instead of 3.5 gallons. Many respondents also reported that residue remains in the bowl even after several flushes.
  • Low-flow toilets clog easily and overflow often.
  • Compared to 3.5-gallon bowls, the 1.6-gallon toilets require more maintenance, therefore making them more expensive due to damage caused by overflow problems.
  • Although not reported as frequently, low-flow toilets keep running and leak more often than older toilets.

The Research Center also conducted a preliminary test to measure and rate the flushing performance of low-flow toilets. Six toilets, all of which were two-piece gravity type designs, were evaluated. Nearly all units required flush volume calibration. Out of the carton, they typically operated below the rated flush volume. On some test units, the flush volume required additional adjustment. By far, the most efficient toilet tested to date is a pressure-assisted model. The Research Center did not find any relationship between performance and price. For more information, go to www.nahbrc.com.

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