Siphon Jet vs Gravity Flush Toilet (A Must Read)

Siphon Jet vs Gravity Flush Toilet: Toilets are no doubt the most useful item in our homes. Purchasing the right toilet can be a much hectic job. When buying a toilet, It would be helpful if you consider aspects: Toilet colors, Dimensions, Type, and, most notably, the Flushing mechanism.
This article will compare the two most populous flushing mechanisms: The Siphon Jet and Gravity Fed toilet, the difference between the two, features, and the PROS and CONS of both flushing mechanisms. Before starting Siphon Jet vs Gravity Flush comparison, let’s begin with knowing some basics of the two flushing systems. Hopefully, the article will help you in deciding the right flushing system for your toilet.

Gravity Flush vs Siphon Jet Toilet

Feature NameSiphonic Jet ToiletGravity Fed Toilet
Water Surface AreaLarge Water Surface Area Approx 7-Inch x 8-Inch.Less Water Surface Area Approx 4-Inch x 5-Inch.
Water Surface LevelAbove the Level of Bowl Outlet.Stays At the Level of Bowl Outlet
Shape of TrapwayTrapway in the shape of “S” or “P” to Create Siphon.It has a simple and straight trapway
Trapway LengthDue to the “S” or “P” shape design, it has a large trapwayIt has a short trapway.
Flushing SystemSiphonic Jet Flushing systemGravity Fed Flush System

Siphon Jet Toilets 

Siphonic jets toilets are the most common toilet type in the US. These toilets create siphon action to jet the water efficiently. This type of toilet has an S-shaped or reverse-P tray way. One end of the trap way is connected to the sewage line and the other to the inlet. The trap way quickly moves the waste down the tubes.

Working Mechanism: How Does a Siphonic Jet Toilet Work?

By pressing the flush lever, the cistern sends water into the toilet’s bowl. You will notice the water in the bowl first rises and subsides rapidly, taking the waste away. You will hear a gurgling noise at the end of flushing, which indicates the vacuum has been broken, and the remaining tank water will fill up the toilet bowl. Due to the reliability and efficiency, these toilets have been gradually gaining popularity.

How Much Water do Siphonic Jet Toilets Use?

Siphonic jet toilets consume 4 gallons of water per flush. Since the Federal government passed a water usage law, limiting the toilet to use no more than 1.6 per flush.

Thanks to manufacturers for redesigning the toilet adhering to the EPA guidelines. Fortunately, the new siphonic jet toilets are still useful, even consuming less amount of water.

Why Choose Siphonic Jet Toilets

One of the siphonic jet toilet’s main selling characteristics is that its water level in the bowl is high. The high water level helps seal noxious gases from plumbing below. Moreover, the siphonic jet leaves a neat and clean bowl. In short, the siphonic jet toilet gives a powerful without making noise.

Must Read: Best Toto Toilet 2022

Our Recommended Siphonic Jet Toilets

Gravity Fed Toilet

Europe’s famous gravity-fed toilets are now gaining popularity in the US. Gravity Fed toilet has a different mechanism than the Siphonic Jet toilets. These toilets use the power of gravity for removing the waste. These toilets are somewhat a great choice if you are concerned with saving water.

Working Mechanism

Gravity-fed toilets have a straightforward working mechanism. They use gravity in the flushing process. Upon pressing the button, water is released and travels directly down into the bowl. Since gravity-fed toilets have a straight trap way, the immense force and weight of water force all the waste out through the trap way. Due to sheer force and water weight, these kinds of toilets are not easy to clog.

Water Usage and Design 

These toilets are designed to reduce water consumption. They offer a dual-flush system, which allows you to choose between a half flush for removing the liquid waste and a full flush for eliminating the solid waste. In half flush, it uses 0.8 gallons and consumes 1.6 GPF for full flush.

Why Choose Gravity-Fed Toilets?

The Gravity-Fed toilet helps in conserving water. The gravity-fed toilet design makes it suitable for small size bathrooms. The straight trap way and flushing mechanism prevent the toilet from clogging.

Our Recommended Gravity Fed Toilets

Siphon Jet VS Gravity Flush Toilet Features Comparison:

siphon jet vs gravity flush

Now you know the basics, let’s compare the different aspects of the two flushing systems.

Water Usage

One of the major differences between the two toilet types is the amount of water it consumes per flush. The gravity-fed toilets are known for their water-saving capabilities. Due to gravity and water weight, it takes less amount of water. Whereas the siphonic jet toilet uses the same amount of water to remove the liquid and solid waste.


Clogging is another category where the gravity-fed toilet dominates. These toilets have large and wide-open traps therefore these toilets are difficult to clog.

Although siphonic jet toilets perform well in terms of clogging. But due to the narrower trap, they can easily get clogged.

Space Savings

Gravity-fed toilets are compact in size and take less space than a siphonic jet toilet. The Siphonic jet toilet needs to be bigger in size so the water strongly flushes the waste.

Noise Levels

Siphonic jet toilets have a low noise level, although there is a rush of air as siphonic jets clear the toilet. Whereas Gravity-fed toilets make a loud noise, which is irritating for some people.

Siphonic Jet Toilet vs Gravity FED Infographics

Siphon Jet Toilet VS Gravity Toilet

Final Verdict 

Choosing between a gravity-fed and siphonic jet toilet can be a difficult task. Ultimately, the choice of toilet will depend on your needs. Both flushing systems have pros and cons. Therefore, it depends on you what you are willing to compromise.

If you decide to opt for a gravity-fed toilet, consider buying Toto Ultramax II, as the toilet offers comfort and a sleek design.

If you decide to buy a siphonic jet toilet, consider American Standard H2 Option, as the toilet has a wide range of features and unbeatable performance. We hope our Siphon Jet vs Gravity Flush system guide helps you, if we have missed anything let us know in the comment section.

Must Read: Best Kohler Toilet 2022

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