Flush Action Comparisons

Toilets are one of our most used home appliances and choosing one to fit our needs demands special consideration. Considering the flushing system should be at the top of your list. Most systems are either siphonic jet or gravity-fed, but which option is better?

Siphonic Jet Models

Siphonic jet units are common in households. With a specific “siphon” method that moves the waste down the tubing and a big water surface and high water level, these have become a standard model used everywhere.

Functions of a Siphonic Jet

toilet with siphonic jet

When you press the flush button, water is released from the tank and enters the bowl. This is why the water first rises and then quickly goes down, taking the waste with it down the pipe. During this process, water entering the bowl comes in faster than it can retreat, creating a powerful vacuum, which rarely leaves any trace of waste behind.

Water Consumption

Ripples of water droplet

Water consumption depends on the model, but on average, siphonic jet toilets use around 4 gallons of water per flush. However, according to new water usage laws, toilets are not allowed to use more than 1.6 gallons of water, which is why most manufacturers had to re-design the way their models work.

Siphonic Jet Toilets rely on high water levels to function. This not only helps keep any odors and gases trapped, but the powerful flush means you spend less time cleaning. In addition, siphonic jet toilets are usually pretty quiet.

Gravity-Fed Models

Gravity-fed toilets are quite popular in Europe and are slowly gaining popularity in the United States, too. These models are an excellent option since they conserve water and help to reduce monthly water bills. Gravity-fed toilets are also eco-friendly, which is another big plus.

Functions of a Gravity-Fed System

Toto gravity fed toilet flushing As the name suggests, these toilets take advantage of gravity to aid the flushing process. The working principle is quite simple. When you press the flush button, water is released from the tank which then passes through the bowl. These models have straight trapways that use water to create enough gravitational force to thoroughly remove matter quickly. Because of this design, these toilets rarely get clogged.

Water Consumption

Unlike siphon jet toilets, these units are designed to minimize water waste. Most units feature a dual-flush design, which gives you the choice of either 0.8 or 1.6 gallons per flush. This ensures you don’t have to empty the whole tank for liquid waste.

Buying a Gravity-Fed Unit

Besides minimizing water waste, these toilets are also small and ideal for compact bathroom layouts. Even better, clogging these models is virtually impossible. The price difference between the siphonic jet and gravity-fed units mainly depends on the style and features you prefer.

Match Up – Siphonic Jet vs. Gravity-Fed

Both types of toilets have their pros and cons, so we couldn’t pick a clear winner. They are both good in their own specific segments.

Siphonic jet toilets have a very powerful flush that leaves the bowl perfectly clean. They are also much simpler to maintain and are pretty decent at preventing odors. On the other hand, these toilets are also prone to clogging and usually take up a bit more space in your restroom. These toilets also use much more water than gravity-fed toilets.

Gravity-fed models are almost impossible to clog and do save water. These toilets are also more compact and lightweight compared to siphonic jet units, which makes them ideal for smaller bathrooms. However, they are not so great at preventing odors and can also surprise you with unsightly waste streaks in the bowl.


The choice between these two types of toilets depends mainly on your needs. Be sure to carefully check the pros and cons of each and clarify exactly what you prefer in a commode. Also, never choose the cheapest unit—although it might look tempting, buying a high-quality toilet is a much better long-term investment.