This section will help consumers sort through all of the old and new jargon when it comes to replacing a toilet in the home or office. We’ll give a brief history of modern toilets, explaining a little about the movement to 1.6 GPF (gallons per flush) in the early 1990s, their continued improvement and the new movement to new HET (High Efficiency Toilet) that use 1.1 GPF to 1.3 GPF.
O.K. basically there are four different types of modern toilets.
1. The Two Piece Tank-Type Toilet – This is the most common toilet and probably the one the consumer is most familiar. It comes in two pieces a tank to hold the water and flushing mechanism and a bowl
2. The One Piece Tank-Type Toilet – This is a tank type toilet made with a single casting so the tank and bowl are combined in one piece. One piece toilets are usually more expensive than their two piece counterparts.
3. Wall Hung Flush Valve Type – This is a toilet that is used mostly in commercial applications, it is usually attached to a fixture carrier. A water closet fixture carrier has two functions, it attaches to the floor and supports the fixture and built into the body of the carrier is a waste receptacle that attaches to the sanitary sewer line. The flushing mechanism is not built into the fixture rather it is mounted above the fixture.
4. Floor Mounted Flush Valve Type – This toilet is mounted on the floor therefore no fixture carrier is needed. The fixture itself supports the weight of the user. It is also flushed with a separate flush valve mechanism.
There are wall hung, tank type toilets, wall hung toilets with flushing mechanisms behind the wall etc. but they are not super common so we won’t go into them here. Look in our Professional Plumbers section for more detailed information on water closets.
Tank type toilets have been around for about a century. Before 1994 tank type toilets were flushed using anywhere between 3.5 and 8 gallons per flush. (Just a side note, the largest use of household use of water is used to flush the toilet.) In 1992 the US Congress passed the Energy Policy Act, basically it said the by 1994 all toilets sold in the US had to be 1.6 GPF or less.
A funny thing happened in 1994 though, manufacturers started making toilets that used 1.6 GPF but most did very little if any engineering to see how almost (2) fewer gallons of water would affect flushing performance. Most used the same bowl with a tank that held less water. The backlash was intense, plumbing contractors were going to Canada to buy 3.5 GPF toilets because customers were complaining loudly.
Because of the negative feedback fixture manufacturers had to go back to the testing lab to improve everything; flushing power, water spot, bowl scouring and the size of the trap way.
Sloan was the first company to revolutionize the 1.6 GPF toilet with its innovative Flushmate pressure assisted system in late 1994. Sloan didn’t actually make the toilet but supplied the Flushmate system for a number of different fixture manufacturers including American Standard, Kohler, Gerber, Crane, Mansfield, Corona, St. Thomas Creations etc. Most companies have tried to copy it but none have done it better. The only complaint we have ever heard about a toilet using the Flushmate system is that it’s a little loud and they have improved in that area over the years as well.
Without getting into too much detail the Flushmate uses a plastic pressure tank that fits inside a porcelain toilet tank. As the bladder tank is filled with water from the water supply it compresses the air inside the tank, when the tank is flushed the air forces the water into the bowl. The waste is pushed out of the bowl by a powerful blast of water rather than the bowl flushing using symphonic action where the waste is actually being pulled out through the trap way.