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San Souci 1-Piece 1.28 GPF Single Flush Elongated Toilet in Thunder Grey, Seat Included

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  • Toilet seat included with purchase
  • KOHLER AquaPiston releases water from 360 degrees around
  • Comfort Height offers chair-height seating (about 2 in. taller)
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Product Overview

The San Souci 1-piece toilet offers a sleek, contemporary design with a convenient chair-like height and elongated bowl for comfortable use. This toilet features innovative AquaPiston technology, a patented flush engine that delivers a fast, powerful, and virtually plug-free flush. A 1.28 Gal. flush provides significant water savings of up to 16,500 Gal. per year, compared to a 3.5 Gal. toilet, without sacrificing performance.
  • 1-piece toilets integrate the tank and bowl into a seamless, easy-to-clean design
  • Compact elongated bowl offers added comfort while occupying the same space as a round-front bowl
  • Low-profile design
  • Comfort Height feature offers chair-height seating that makes sitting down and standing up easier for most adults
  • 1.28 GPF (gallons per flush)
  • Concealed trap-way and low-profile bolt caps facilitate easier cleaning and enhanced design
  • Includes K-4008 Grip-Tight reveal Q3 seat
  • Standard left-hand trip lever included
  • Supply line not included
  • Single-flush gravity uses the force of gravity and a precision-engineered tank, bowl and trap-way to create a strong siphon during flushing
  • AquaPiston canister allows water to flow into the bowl from all sides (360°), increasing the power and effectiveness of the flush
  • Flush valve's 3:2 ratio harnesses the natural force of gravity and optimizes flush performance
  • Durable canister design has 90% less exposed seal material than a 3 in. flapper, for leak-free performance
  • Light-touch canister flush requires a lower actuation force than a flapper
  • Standard 12 in. rough-in
  • WaterSense toilets meet strict EPA flushing guidelines, including using at least 20% less water than 1.6 Gal. toilets
  • Eligible for consumer rebates in some municipalities

  • Features to consider when buying a toilet

Info & Guides

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Bowl Height without Seat (in.)
Flush Valve Size (in.)
Product Depth (in.)
27.5 in
Product Height (in.)
25.3125 in
Product Width (in.)
16.375 in


Bowl Height
Chair Height
Bowl/Seat Shape
Color Family
Thunder Grey
No Additional Features
Flushing Technology
Gravity Fed
Flushing Type
Single Flush
Gallons Per Flush
Handle Location
MaP Performance Rating
Vitreous China
Mount Location
Floor Mount
Product Weight (lb.)
94 lb
Rough In Size
12 inch Rough In
Seat Front Type
Toilet Type
Trapway Diameter (in.)
Trip Lever Location
Left Side

Warranty / Certifications

Certifications and Listings
ADA Compliant,ANSI Certified,EPA Approved
Manufacturer Warranty
1-Year Limited Warranty

Questions & Answers

Typical questions asked about products:

  • Is the product durable?
  • Is the product easy to use?
  • What are the dimensions of the product?

Customer Reviews

  • 4.5
    out of 155 reviews
  • 83%recommend this product
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Showing 1-10 of 155 reviews
Worst toilet ever
Toilet has a leak and Kohler has sent me parts for it at least 4 times now and it still leaks. What happens is every 2-3 hours due to leak the toilet does an incredibly loud fill sound. I’ve been sleeping with ear plugs. Home Depot install was here three times but they are not plumbers so can’t help. I finally reached my final straw when Kohler sent me a used replacement part (supposed to be a new part) with cracks in it that doesn’t even look like it fits. I called Home Depot today who told me to uninstall it and return it. Like that’s easy for a woman to do. Now I have to hire a plumber to uninstall it and put in my car to return it. Worst customer service from Home Depot and Kohler. Beautiful looking toilet in cashmere but not worth the noise and wasted water filling the tank. Oh and the seat is cheap looking and the lid scratches easily. To buy a replacent lid you have to buy the $100 seat. Awful just awful!!
Response from Kohler Product ExpertJul 26, 2021
Hello, this is Sarah with Kohler Co. I'm sorry to hear your toilet is leaking and that after replacing parts, you are still experiencing the leak. We would recommend performing a water test to narrow down the location of the leak. Please follow this link for an explanation on how to perform this test: https://bit.ly/2O4cg0R. Please email our Customer Service team directly at KohlerCustServ@kohler.com with the results. We look forward to helping you soon!. -Sarah S. Kohler Customer Service
    2 people found this helpful
    Quality, function, look and comfort impressive. Installation service from...
    Quality, function, look and comfort impressive. Installation service from Home Depot could not be happier with the work. Easy flush and look forward to saving on water use with this 1.2 gallon tank.
    • Verified Purchase
    2 people found this helpful
    I'm a big fan of Kohler toilets. They work well, and I like the AquaPiston flush mechanism much ...
    I'm a big fan of Kohler toilets. They work well, and I like the AquaPiston flush mechanism much more than the "flapper" designs. When I moved into my house 4 years ago, I replaced two of the oldest toilets with Kohlers and they have worked flawlessly. I chose this Kohler San Souci model to replace an American Standard toilet that worked okay but has had several problems with the flush mechanism that I've had to repair. Before purchasing any toilet, make sure to watch the Home Depot video on YouTube called "How to Replace or Install a Toilet". The very first step they recommend is to measure the "rough in"--the distance from the wall to the center of the bolts on the base of the toilet (where the 'closet flange' is located). I'm very glad I watched that video. I only measured the rough-in after I had the toilet, and I discovered that the prior homeowner had installed the closet flange less than 11" from the wall during a remodel that added the bathroom to my house. This Kohler toilet is a standard 12" model, and would not fit on my existing closet flange location. I called my handy man and he had to remove the old flange, cut out the porcelain tile and mortar, replace some of the toilet drain pipe, and install an offset toilet flange (Home Depot SKU 190020), which was a pretty major project and took him half a day due to the way that the toilet drain pipe was installed in my concrete slab. But the new offset toilet flange provided a perfect 12 inch rough in distance, and this Kohler toilet then installed perfectly. The toilet itself is very nice. It's a clean, minimalist design with a very small tank. It's remarkable that it only uses 1.28 gallons per flush, yet it works well and flushes effectively. And a side benefit of the smaller tank size is that it refills quickly, so the water noise from refilling is minimized. The base and bottom sides are smooth with relatively very few corners and crannies, making this toilet very easy to clean. And the special bolts that come with the toilet install with a flat head and shallow plastic cover on the base, making the base very easy to clean--there are no large bolt 'bumps' on the base. One downside to the special bolts on this toilet is that they require a near ideal closet flange installation, as you have to slide a special nut into the closet flange (see photos), and those nuts need to be supported by something, such as a floor or subfloor. In my case, the concrete foundation had a gap between the toilet pipe and the concrete foundation, so there is a gap under the toilet flange, and there was nothing to support the special flange nuts. My handy man had to use plumbers putty to build a support for the nuts so they wouldn't fall out. So just be aware of that when installing. The toilet seat included with this model is a soft close, which I really like and have on all of the toilets in my house. The only issue is that the toilet seat lid is a somewhat soft semi-gloss plastic, and it was covered in large scratches by the time the install was finished. The scratches are only visible at an angle and if you are looking for them, so I don't normally see them, but just be aware that the toilet seat lid does scratch easily. Other than those two minor items, this is a great higher-end toilet. I would recommend this model and any other Kohler AquaPiston toilet.
    • Recommended
    27 people found this helpful
    I recently upgraded the toilet in my bath to a new Kohler San Souci Comfort Height One-Piece Elon...
    I recently upgraded the toilet in my bath to a new Kohler San Souci Comfort Height One-Piece Elongated Toilet. This is the second San Souci toilet I have owned and really love the design. I’m very impressed with the performance and sleek design and contours of the toilet. The integral tank on the San Souci one-piece toilet is much smaller than a conventional two-piece toilet, but has sufficient capacity for the 1.28 gpm flush using the efficient AquaPiston Canister flush system. It has a comfortable height of 16.5 inches and a shallow depth of only 27.5 inches, making it ideal for small spaces. It also includes a soft close toilet seat that snaps on and off for easy cleaning. The one-piece design prevents leaks common in two-piece toilets from holes attaching the tank to the bowl. Cleaning behind the seat is also easier with a one-piece toilet. The only negative aspect of the San Souci Toilet is high cost, which is common with all one-piece toilets. However, the quality and functionality of the San Souci toilet are outstanding. Highly recommenced!!
    • Recommended
    10 people found this helpful
    The toilet comes with a nice slow-close toilet seat and the AquaPiston is pre-installed, so you o...
    The toilet comes with a nice slow-close toilet seat and the AquaPiston is pre-installed, so you only have to set up the sensor which is very easy to do. The toilet seat is not the most comfortable seat, but it’s a good quality seat. What I like best about this toilet is the modern look, the powerful AquaPiston flush, and the easy installation. This is the second time I install a toilet that comes with tall guides and it’s great because you can see the guides while lifting the toilet so you know when it’s in the right location. Once you set down the toilet, you put your fingers on the plastic guide, then you take out the guide and it tells you which size bolt to use to tighten the toilet (comes with 3 bolt sizes). The bolts end up being flushed, so they don’t stick out like traditional toilet bolts making it so easy to clean. I made mine into touchless by buying the Kohler Touchless Flush kit sold separately.
    • Recommended
    6 people found this helpful
    This is the nicest toilet I've ever seen or sat on. I know it's expensive but if you plan to kee...
    This is the nicest toilet I've ever seen or sat on. I know it's expensive but if you plan to keep it for years you won't be disappointed. It weighs in at 94 pounds and is rock solid. I'm not sure why two piece toilets still exist after installing and using this. It's a much better design and looks, in my opinion, a lot better. I was a little skeptical about the 1.28 gallon tank at first but we haven't had any problems with it, at all. To fully test it, my wife wasn't really happy with this, I flushed a few bananas. First a half, then a whole one. Just for fun I tried 2 at the same time. Not a single problem with any of it. Everything about this toilet is top notch. From the bolts holding it down, to the no slam seat with a lid that covers the actual seat, I can't imagine anything better than this. One more thing. The instructions say to use a wax ring on install but I choose the fancier and a bit more expensive toilet gaskets and had it installed in under an hour.
    • Recommended
    18 people found this helpful
    This is a very nice looking toilet, I like how small the tank is and does not overpower a room no matter the size of the room. Its nice to see this brand getting away from the typical large tank type industrie standard. Installation was a breeze, that part is very typical. They give you some fancy new flush (as in flat) to use on the hub but it was very difficult to use as my hub was above my floir line and didnt retain the bolts when i was trying to place the toilet on the hub. I eventually uses standard hub studs with dome caps, not as nice as the flush heads but i didnt have a choice. I would be only one to ever notice. Suffice to say you dont have to use the hardware they give you but make sure you use a washer so you dont crack the base. The function of the toilet is great. All solids flush easily and fast. The insise tank mechanisim looks pretty fancy but i didnt notice much differce from other similar pruce toilets ive installed. My only grip is the flush lever linkage was a bit loose and jiggly, not something id expect at this price range. Might need to see if i cant do something about that later. All in all, the best thing about this toilet is that it looks great. The second best thing is the function. Aside from a jiggly handle, i see no reason not to purchase if it wirhin your budget.
    8 people found this helpful
    Great Product
    We bought this with our bathroom renovation. The original delivered product was destroyed in shipping and Kohler immediately replaced it within a week. They truly have unparalleled customer service. The unit itself is very solid and the pressure it gets when flushing is amazing for a toilet this size. Very comfortable.
      • Recommended
          Showing 1-10 of 155 reviews