House Grail is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Siphonic Jet vs Gravity-Fed Toilet: Which One Should You Choose?

modern bathroom

Toilets are arguably the most useful item in our homes. It is, therefore, important to have the right kind of toilet to ensure that it serves you well.

One of the most important factors to consider when looking to get a new toilet is the flushing mechanism. There are two main types of toilets in that regard: the siphonic jet and the gravity-fed toilet.

Which one is better? Let’s find out.

house dividerWhat Is a Siphonic Jet Toilet?

Siphonic jets are the most common type of toilet in the United States, and with good reason, they work extremely well. A siphonic jet toilet features an S-shaped or reverse-P trap way, with one end connecting to your home’s plumbing and the other to the inlet from the bowl.

This trap way design works to create a siphon that forces waste matter down the tubes. In addition to the S- or P-shaped trap way, siphonic jet toilets have a large water surface, and their water levels are always being above the bowl outlet.

toilet flushing
Image credit: Am.p, Shutterstock

How Does a Siphonic Jet Toilet Work?

After pressing the flush lever, the cistern sends water into the toilet’s bowl forcefully. As such, you will notice the water in the bowl first rises before it subsides rapidly, thereby taking the waste with it.

This action is by design, as it involves the tank releasing water at a faster rate than it can exit the bowl. When that happens, a vacuum (siphon) is created, which pulls the waste out. This siphoning action is so powerful that these toilets rarely leave waste or streak marks in the bowl.

After a few moments, you should hear a gurgling noise, which indicates that the vacuum is broken. The remaining water in the tank will then replace the one that the bowl lost.

How Much Water do Siphonic Jet Toilets Use?

Most siphonic jet toilets use around 4 gallons of water per flush. However, since the government enacted water usage laws that require a toilet to use no more than 1.6 gallons of water per flush, manufacturers of siphonic jets have had to rethink their designs to adhere to the guidelines.

Fortunately, the new siphonic jet models are still able to work efficiently, even when utilizing considerably less water per flush.

Why Choose Siphonic Jet Toilets

As mentioned, one of the telling characteristics of a siphonic jet toilet is that its water level in the bowl is quite high. Having a high water level is advantageous, as it helps seal noxious gases from the plumbing below. Siphonic jet toilets can have a water level that is twice as high as that in gravity-fed toilets.

Additionally, siphonic jet toilets generally leave cleaner bowls, as they rarely leave waste or skid marks in the bowl. Again, even though they have a powerful flush, it is quite silent.

What Are Gravity-Fed Toilets?

Gravity-fed toilets are the staple in most of Europe. However, more and more Americans are choosing them, as they limit water wastage.


How Do Gravity-Fed Toilets Work?

As you can tell from their name, they manipulate the force of gravity to aid in the flushing process. Nonetheless, it is not as complicated as it sounds, as the mechanism is quite simple; upon pressing the button or lever, the tank forcefully releases water and sends it directly to the bowl.

Since gravity-fed toilets feature straight trap ways, the sheer weight of the water creates a gravitational pull that forces water and waste through the straight trap way. As a result, these kinds of toilets rarely have clogging problems.

How Much Water Do Gravity-Fed Toilets Use?

As mentioned, gravity-fed loos are designed to minimize water wastage. They typically come in the dual-flush design, which allows you to choose between a half and full flush after use. A half flush uses 0.8 gallons, while a full flush uses 1.6 gallons. This means that you do not have to empty the tank after every short call.

Why Choose Gravity-Fed Toilets?

In addition to helping you conserve water, gravity-fed toilets also take up less space due to their design, which makes them ideal for smaller spaces.

Additionally, their straight trap way, as well as flushing mechanism, ensures that clogging is almost an impossibility.

Siphonic Jet vs Gravity-Toilets: Pros and Cons

Each of these toilet types has unique advantages and drawbacks. Let us pit them against each other:

siphonic jet vs gravity fed
Left: American Standard H2Option | Right: Toto UltraMax II
Siphonic Jet Pros
  • Powerful flush action that leaves cleaner bowls
  • Easy to maintain
  • Limited odor
Gravity-Fed Pros
  • Impossible to clog
  • Saves water
  • Uses up less space
Siphonic-Jet Cons
  • Prone to clogging
  • Uses a great deal of water
  • Take up space
Gravity-Fed Cons
  • Susceptible to skid marks
  • Can be smelly
Image Credit: Pixabay

tool dividerSiphonic Jet vs Gravity-Fed Toilet – The Verdict

Ultimately, the choice of toilet will depend on your needs and preferences, as both have unique advantages and drawbacks. Therefore, it is a matter of what you are willing to compromise.

If you decide to get a gravity-fed toilet, consider TOTO Ultramax II, as it offers you the benefits of a gravity-fed toilet while limiting drawbacks such as susceptibility to skid marks. It is also quite comfortable.

If you desire a siphonic jet toilet, then consider American Standard 2887218.020 H2 Option, as it is extremely powerful and still limits water wastage.

The choice is yours to make. If you do have questions, however, do not hesitate to reach out to us, as we will be glad to help make things clearer for you.

Featured Image Credit: New Africa, Shutterstock

Related posts

OUR categories

Project ideas

Hand & power tools