Gravity Tank Toilets:
Gravity tank toilets, which have a bowl and a tank, are most commonly found in residential settings but are in some commercial/business settings. They depend on the volume of water in the tank to flush wastes and usually require water pressure of no more than 10 - 15 pounds per square inch (psi) to operate properly. The tank and bowl are usually two separate pieces, although this is not obvious once are in use. A few one-piece toilets are also available. Gravity tank toilets are relatively inexpensive, with retail prices for two-piece toilets ranging from $75 - $150 and one-piece models costing somewhat more.

Pressurized Tank Toilets:
This relatively new design uses water line pressure to achieve a higher flush velocity. Water is not stored inside the tank, but in a tank that compresses a pocket of air and releases pressurized water into the bowl and out the trapway. They require a minimum water pressure of 25 psi to operate well. Retail prices for these toilets are generally over $150.

Flush Valve Operated Toilets:
This is the type of toilet usually found in many public restrooms. These toilets have no tank. Instead of a storage tank, this toilet uses a valve directly connected to the water supply plumbing of a building. This valve controls the quantity of water released over time by each flush. Flushometer valves are typically made by one manufacturer and the china bowl by another. It is very important that there is a proper match between the valve and the bowl when purchased. Unlike tank-type toilets, flushometer valve toilets must accommodate different water pressures at different points in a building. Flushometer toilets usually require a minimum water pressure of 25 - 40 psi to operate well. The are priced at about $250 for both the valve and the bowl.

Floor-Discharge Drain Line:
This toilet is usually bolted to the floor. They can be gravity, pressurized or flush valve type toilets.

Wall-Discharge Drain Line:
This toilet is usually attached to the wall, rather than the floor. They can be either gravity or flush valve type toilets.