Kohler San Souci – Full Toilet Review

The San Souci is truly a unique toilet. In fact, I’ve only seen this a couple times in the wild! One of these times that we got to see this toilet was in a showroom. It’s actually a little smaller in real life than I expected.

Which is a big advantage, as it turns out. The San Souci excels in smaller spaces, and you can certainly see why when up close. But more on that later!

Kohler San Souci

Unique and compact one-piece.

What People are Saying

Most people, ourselves included are fans of this toilet. Aside from its unique and attractive design, it’s also a perfect toilet for a smaller bathroom.

The width is pretty standard, but the height and depth are several inches shy of the averages of most toilets. This can be an asset if you plan to put the San Souci in a tight space, or simply want to free up room. And while we’ll be looking at the round version in our review, there’s also a compact elongated version.

What We Like About the Kohler San Souci

One could be forgiven by confusing the San Souci with the San Raphael, or even the Santa Rosa. They definitely have design similarities. Like those other models, one of the things we gravitated to in looking at this model was the shape. If you haven’t noticed yet, Kohler definitely likes to mix up their designs!

Aside from that, like we mentioned we really like the compactness of this model. It would likely not be the most ideal toilet for older or disabled individuals, but could be perfect for anyone that has a limited amount of space.

The Dimensions

Take a look at these measurements to give you an idea of what you’ll be getting with the San Souci, and if will work for your bathroom.

  • Rough-in: 12 inches
  • Trapway: 2.125 inches
  • Height: 24.25 inches
  • Depth: 25.62 inches
  • Width: 16.75 inches
  • Seat height: 16.5 inches
  • Flush: 1.28 GPF


The San Souci was designed for a standard, easy installation. This is the case with many Kohler toilets. Thanks to its floor-mounted design, once you’ve got the toilet into position, the rest should be painless. The mounting bolts are exposed and easily accessible, and there are no special procedures or mounting materials and tools required.

Flush Strength

The Kohler K-4007 San Souci Toilet includes a patented AquaPiston flush engine and a flapper-less flush valve. In addition, its exclusive canister design and seal eliminate leakage problems regularly associated with conventional rubber flappers.

The flush strength is one of the essential features of a toilet. For the context of how the AquaPiston flush engine benefits the flush, here’s a brief explanation of what the flapper is. Feel free to skip over the next paragraph if you already know these details.

What Is a Flapper?

A flapper is a device inside the tank made from rubber. Its purpose is to control the water flow whenever you hit the flush. Eventually, the flapper deteriorates because of chemical cleaners and general wear and tear, and this can cause a leak to occur. So with a flapper-less toilet, one using AquaPiston flush engine technology, there’s no need to worry about that part getting worn out or damaged.

OK, back to the AquaPiston.

The AquaPiston canister takes in water from 360 degrees to ensure a smooth and consistent water flow to the bowl and a powerful, plug-free flush. The Kohler San Souci is WaterSense certified. This means the product is supported by the U.S. Environmental Protection Agency (EPA) for meeting its criteria for efficiency and performance.

WaterSense-labeled products and services are licensed to use at least 20% less water, are more energy-efficient, and perform as well as or better than regular models. In this case, the San Souci uses at least 20% less water per flush than 1.6-gallon toilets. Compared to a standard 3.5-gallon toilet, its 1.28-gallon flush can save up to 16,500 gallons of water per year, giving you considerable savings on your water bill without compromising performance.

Trapway Size

The bigger the trapway or the discharge passageway in the toilet, the quicker the water and waste leave the toilet. Trapway sizes range from the industry-standard 2-inch diameter to the industry-leading diameter of 2-3/8-inches. The Kohler San Souci has a reasonable trapway diameter of 2-1/8-inches.


According to the Americans with Disabilities Act (ADA), toilet seats need to be between 17 to 19 inches high for easier sitting and standing. This measurement is taken from the floor to the top of the seat. From the floor to the bowl rim, the San Souci toilet has a seat height of 16.5 inches, which falls short of this requirement.

Even so, the ADA requirement is primarily for commercial purposes. So even though the San Souci isn’t ADA compliant, and you’re ok being half an inch short of that measurement, then this can still be a viable option for you.

Design and Construction

The San Souci one-piece toilet makes a powerful design statement with sleek curves and a low-profile outline. The small tank arcs seamlessly into a round-front bowl, offering a space-saving shape. In addition, its built-in soft-close seat is designed using innovative technology to prevent slamming.

The smooth, streamlined design of a one-piece toilet like this product makes it more hygienic and easier to clear because there are fewer spots that store dirt where germs can breed. In addition, its low-profile tank and round-front bowl make it one of the most miniature toilets around, ideal for powder rooms and small bathrooms.

From the back of the tank to the front of the rim measures an overall depth of 25-5/8 inches. As a result, children will have an easier time using them. In addition, although it’s not yet definitively proven, some people believe the round bowl shapes help the toilet flush more efficiently.

Bells and Whistles

Kohler has always been big on incorporating technology into their designs. Here’s how the technology used and additional features help to make this a game-changing model:

  • It offers a powerful and effective flush with an AquaPiston canister, allowing water to flow into the bowl from all sides.
  • Its flush valve’s 3:2 ratio controls the natural force of gravity and enhances flush performance.
  • The sturdy canister design has 90% less unprotected seal material than a comparable 3-inch flapper for a leak-free operation.
  • Its design allows solid drain-off during flushing thanks to the single-flush using gravity and a precision-engineered tank, bowl, and trapway.
  • Its light-touch canister flush needs lower actuation force (the amount of pressure required to register a press) than a flapper toilet.
  • It offers a low-profile design with a Reveal Quiet-close seat and grip-tight seat to prevent it from shifting.
  • Available in four different colors: white, biscuit (beige), black, and ice gray.

The Kohler San Souci “Toilets In The Wild” (learn about “In The Wild” photos here). This photo was taken in a showroom.

“In The Wild”

Kohler San Souci

Where the Kohler San Souci Toilet Could Be Improved

For a more inclusive design, it could benefit from meeting the comfort height requirements of measuring 17-19 inches from the base to the seat. The San Souci measures 16.5 inches from the toilet base to the top of the seat, making it standard height. It seems they aimed for a super small toilet but have waived comfortability and inclusivity in doing so.

Some customers have complained about the quality of the toilet seat not being as strong as it could be. This is because the seat joins with drywall-like anchors. If an anchor breaks, the toilet seat will be slack until you purchase a Kohler toilet seat repair kit or you’re ready to buy a new toilet.

The San Souci’s price point is a little high for a standard-height toilet. However, its efficiency and aesthetic more than make up for the cost difference. You’ll be expected to pay between $650 (for white) to $1000 (for black) depending on where you purchase the toilet.

The ToiletsMan Verdict

The San Souci model from Kohler is a solid pick for a toilet, no doubt about it. That said, we feel that this model caters to a specific situation.

Specifically, anyone who has a smaller space to put their toilet, but also has (1) the right budget, and (2) a desire for a more unique design. There’s no question that the San Souci can handle the job, but so can a lot of other toilet models. So if you don’t fall into both of those categories mentioned above, we would suggest continuing to look for other models.

If you are one of those people that falls into those categories, then the San Souci should shoot near the top of your list, as the combination of compact design + technology is hard to duplicate elsewhere.

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