How does a toilet work?
When a standard residential toilet, called a gravity toilet, is ready for use, both tank and bowl contain water. When the lever is pressed, it lifts a rubber stopper, called a flapper, which lets the water in the tank flow into the bowl. The water enters the bowl through small holes around the inner bowl top and at the siphoned jet hole at the base of the bowl. Gravity forces the bowl's water and waste down the waste pipe. The water flowing into the bowl also cleans the bowl. The bowl's water is replenished by water entering from the tank through a refill tube.
Inspection
Inspectors should check for the following defects and perform the following tests:
Note: Inspectors should never operate the water shut-off valve behind the toilet, or any other water shut-off valve.
Alternative Toilet Designs
Pressure-assist toilets: This 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. Although pressure-assist toilets are somewhat noisy during flushing as pressure is released, up to 80% of the flush water is used to purge the bowl, making for a very efficient flush. These toilets work well as long as the household water pressure is at least 25 pounds per square inch. 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. Pressure-assist toilets are generally better than typical gravity toilets, but the more complicated mechanism makes them more expensive to buy and repair.