Types of toilets

Gravity vs. pressure-assist toilets

Toilets consume 30 percent to 40 percent of the total water used in homes, making them the biggest water users. Replacing an older 3.5-gallon toilet with a 1.6-gallon toilet could save an average of two gallons per flush, totaling a household savings of 12,000 gallons of water per year. Dual-flush 1.6-gpf toilets further reduce water consumption by about 25 percent.

You might want to check with your local utility company; many municipalities offer rebates that can defray the cost of a new, more efficient toilet. City municipalities that have installed 1.6-gpf toilets report reduced total water demand and reduced wastewater flow of 15 percent to 20 percent, saving taxpayers millions of dollars per year.

Toilets come in several main types: pressure-assist, power-assist, vacuum-assist and gravity. Be sure to compare like categories when you are shopping. Otherwise, you end up comparing apples to oranges. In general, reviews say to expect to pay between $250 and $400 for a good toilet.

Gravity toilets: This is the most familiar type of toilet. Here, water drops from the tank into the bowl and trap, moving waste down the drain. Gravity does all the work, which makes them a good choice for homes that don't get great water pressure (as low as 10 pounds per square inch should be fine). Gravity toilets have a proven design and appeal to those who want a quiet flush. Since there's not much fancy technology inside the tank, repairs are easier. However, lower-priced models don't typically fare as well in testing. The best gravity toilets can cost as much as pressure-assist toilets. Prices range from about $150 to $500.

Pressure-assist toilets: These are the most powerful toilets, best suited for large families or heavy use. The toilet's water supply provides the pressure to compress air within a sealed plastic reservoir inside the tank. When the incoming water reaches the fill line, the tank is pressurized and ready for the next flush. During flushing, the air under pressure creates a loud "whoosh" as water blasts into the bowl; this noise can startle small children and people who like to flush while seated. Up to 80 percent of the flush water is used to purge the bowl, making for a very efficient flush. These toilets work great as long as the household water pressure is at least 25 pounds per square inch (psi). Pressure-assist toilets can solve problems in homes with older plumbing systems where gravity-fed 1.6-gpf toilets just aren't strong enough to pull waste through the older pipes. Prices generally range from $225 to $400. Pressure-assist toilets are generally better than gravity toilets, but their more complicated inner workings make them harder to repair.

Vacuum-assist toilets: In these toilets, the tank houses a vacuum chamber that works like a siphon to pull air out of the trap below the bowl so that it can quickly fill with water to clear waste. These toilets, like power-assist models, work well in close quarters or bathrooms located near bedrooms, where you'd want a quiet toilet. Vacuum-assist toilets typically have less power than pressure-assist toilets, and are not as widely manufactured as other toilet types, so there are fewer choices. In general, these toilets range in price from $200 to $350. In reviews, experts recommend pressure-assist toilets over vacuum toilets.

Power-assist toilets: Power-assist toilets plug into a standard GFCI outlet and use electricity to power a pump that pushes water into the toilet bowl. These quiet operators work well in close quarters or bathrooms located near bedrooms. A self-closing seat, which may be added to any toilet for about $50, eliminates the loud clanking associated with a toilet seat dropping on porcelain. This type of toilet is expensive; prices start at about $900. The designer Kohler Hatbox toilet, for example costs about $2,800.

In home-improvement stores, you'll see familiar-looking two-piece toilets alongside newer one-piece toilets. The one-piece models incorporate the tank, bowl and seat into one piece of hardware. A one-piece toilet is easier to clean, doesn't leak between the bowl and tank, and is typically more expensive than a two-piece toilet. The tank and bowl are separate in two-piece toilets, and the toilet seat is usually not included with the bowl. Two-piece toilets are usually less expensive than one-piece toilets, but they're a little harder to clean.

The vast majority of toilets still mount on the floor over a trap that leads to the sewer main. But you can also find wall-mounted toilets, which require a special plumbing setup. Wall-mounted toilets are more expensive, generally over $500. A wall-mounted toilet allows for easier floor cleaning.

Toilet bowls are available in two basic shapes -- round and elongated. Round bowls save space; elongated bowls are more oval in shape, and are a bit more comfortable as well. Elongated bowls are usually 2 inches longer than round bowls. With their larger water surface, elongated bowls are recommended by the ADA for seniors or those with disabilities.