Tuckers Air Conditioning, Heating & Plumbing Blog

Plumbing Basics: How a Bathroom Toilet Works

The toilet. It’s not a piece of equipment in a home people talk about much, but it’s also about as essential as home equipment gets. Few indoor plumbing inventions are better than the toilet, after all!


Any plumber in Germantown, MD or the surrounding areas who’s worth hiring knows all about the design and workings of a toilet so they can repair them. But how much do you know about how a toilet works? If you’re interested—and knowing this can help you understand when it’s time to call for plumbing help—we’ve got a short rundown on the basics of the modern bathroom toilet and the different models.

The Gravity Toilet

Sounds like a science-fiction device, doesn’t it? But the gravity toilet is the most basic type of toilet, and probably the one you’ve got in your bathrooms. These toilets use the most basic force to operate—gravity.

This is why old-fashioned toilets had a tank high up on the wall. When the flush chain was pulled, the water from the tank had to drop that long distance to create enough force to flush out the bowl. The modern toilet doesn’t need that kind of distance between tank and bowl, but the idea is the same: the flush lever pulls open a flapper that sends the water collected into the tank down into the bowl. The tank then fills up with water through the feed line and stops when a float rises high enough to shut off the water.

Newer toilet designs are more efficient, so that the smallest amount of water in the tank is used to flush. Low-flow toilets can use as little as 1.28 gallons per flush. Those old high water tank toilets could use up to 6 gallons per flush.

Pressure-Assisted Toilets

These are more often installed in businesses or hospitals, but homes may find them useful as well. Pressure-assisted toilets use pressurized air to force the water from the tank, making a distinct whoosh noise when they flush.

To have a pressure-assisted toilet installed, a home needs to have the right level of water pressure. Lower water pressure than needed can indicate a home is losing water through leaks.

Dual Flush Toilets

This is an invention to help make low-flow toilets more effective. The design of the toilet isn’t much different from a standard gravity toilet. However, it has two different flush buttons. One flush button allows a smaller amount of water from the tank, while the other uses the whole tank. The first flush is for liquid waste only, and the second is for solid waste. This prevents the toilet from having to be flushed more than once, which is a complaint some people have about low-flow toilets.

Older toilets can be retro-fitted as dual flush toilets. Ask a plumber about how this can be done for your current toilets, or if the better course is to have new toilets installed.

Schedule great plumbing service! Tuckers Air Conditioning, Heating & Plumbing has served Gaithersburg and Montgomery County since 1995.