Our staff has found that the best way to evaluate the performance of a flushometer toilet is to tear up about 50 sheets of toilet tissue and drop it into the bowl. After the paper has submerged below the water line, flush the toilet, keeping an eye on the second hand of a watch.
Note: Under normal pressure, the standard Sloan™ or Zurn® Flush Valve will run approximately 1/2 gallon of water per second during a normal flush cycle. A new Sloan™ A-38-A Kit and pressure cap should have a flush cycle of between 7 and 9 seconds. This time sequence would use between 3.5 and 4.5 gallons of water per flush.
When the flush cycle begins, carefully watch the tissue in the bowl. Once the paper has totally cleared and the bowl is clean, the flushing cycle has achieved its objective. Now, quickly look back at your watch second hand again; the water that continues to rush through the bowl after it has cleared is now being wasted. A flush cycle that lasts for a total of 10 seconds (or about 3 seconds after the bowl is cleared) is usually wasting between 1 to 2 gallons per flush, while a flush cycle lasting a total of 15 seconds (or about 8 seconds after the bowl is cleared) could waste as much as 4 gallons of water per flush.