Most toilets fall into two basic types: gravity feed and pressure assist. Gravity feed toilets dominate the market. We didn't include vacuum-assisted toilets in our latest tests because they're so noisy, and because they've practically disappeared from the marketplace. Here are the two types of toilets to consider.
As their name implies, these toilets rely on gravity. Water drops from the tank into the bowl to move waste down the drain. They can work with as little as 10 psi of household water pressure.
Gravity-feed toilets flush more quietly than pressure-assisted models. Many we tested worked every bit as well as the best pressure-assisted models, and with far less fanfare--an advantage in close quarters.
Models that perform comparably to pressure-assist units typically cost as much, while lower-priced models may not be up to the job.
These make up about 10 percent of all toilet purchases. As water displaces air within the sealed tank, it creates pressure that thrusts waste forcefully out through the bowl. A pressure-assisted toilet is an especially good choice for large families. But it does have a noisier flush, which can be a privacy problem. Before buying this type, be sure that your home has at least 25 pounds per square inch of water pressure, the minimum required for a pressure-assisted toilet to work properly. You can check with a $10 gauge that connects to an outdoor spigot.
The pressure-assisted toilets dispatched our simulated solid waste with few clogs.
These toilets are noisy; the loudest ones emitted an emphatic whoosh. They can be expensive.