Kohler Harken Toilet Full Review

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In this reivew, we are introducing the Kohler Harken toilet. This Kohler toilet features a smart flush technology and uses only 1.28 gallons per flush.

We have listed all the features, product documentation and even looked into the customer reviews and manufacture facts for you to make the best judgement of the Kohler Harken toilet yourself!

Enjoy the review below and be sure to check our vast resources and how-to guides too.

The Kohler Harken (Full) Toilet Review of 2023

Our experts reviewed and collected facts about the Harken toilet all right below!

“At Toiletable, we are no stranger to Kohler toilets. We love the Harken because of its funky design, smart flushing technology, and comfortable design.”



Key Features
  •  Flush Score:   1000 MaP
  • Water Consumption: 1.28 GPF
  • Bowl Shape: Elongated
  • Flush Type: Single
  • Style: One-Piece
  • Certifications: WaterSense, CEC
  • Dimensions :
    • Toilet – 29.81″ x 15.68″ x 26.81″
    • Rough-in – 12″
    • Trapway – 2.12″
    • Seat Height – 16.125″
See image with toilet dimensions
  • 1.28 gpf
  • Unique design of tank and trapway
  • Quiet Close Seat included
  • Expensive when compared to more affordable yet decked-out Kohler toilets



This one-piece toilet is eco-friendly and reliable.

Flush Power

The Harken is a one-piece, compact elongated toilet with a 1.28 gallons per flush (GPF) rating, which is considered a standard flush rate. The toilet has the highest MaP score possible of 1,000 grams.

The toilet utilizes Kohler’s AquaPiston flush technology. Using a piston-like action to push water into the bowl, the toilet’s flushing system creates a more efficient and effective flush. The system uses a canister design that allows water to flow into the bowl from all sides, which helps to keep the bowl cleaner and reduces the potential for clogs.

The toilet’s larger flush valve allows more water to enter the bowl faster and provides a more powerful flush as well.


The compact elongated bowl shape of the Harken is designed to save space without compromising comfort. The Harken is not ADA-compliant but has a seat height of almost 15 9/16” which is relatively comfortable for most adults.

The Harken comes with a left-hand polished chrome trip lever that needs to be pushed up to be activated. It’s a small detail that we think makes the Harken a little bit more unique. That being said, the whole toilet’s design is very distinct.

Notice the toilet’s wide, rounded tank which seamlessly flows into the toilet’s skirted trapway. The crown molding at the top of the tank and at the bottom of the trapway brings the whole piece together wonderfully.

Another bonus – the toilet’s skirted trapway makes it extra-easy to clean, as bacteria doesn’t have anywhere to go.

The Harken comes with a Quiet Close Seat, so no more annoying toilet seat slamming when you’re in a rush.

Though this is a bonus that many toilets don’t include, the Harken’s price is a bit expensive for what you get. For the cost of this toilet, we think you would be able to get more features, such as a deodorized seat or a dual flush mechanism, like the Kohler Highline. Nevertheless, the Harken is a solid unit that delivers on all its promises.

The toilet only comes with white and requires a 12” rough-in. A supply line can be purchased separately.




Color Option

  • white

Seat Option

  • K-20110 Brevia™ Quiet-Close™ elongated toilet seat

Product Documentation


Summary of Customer Reviews

Positive reviews boast about the toilet’s flushing performance, noting how the efficiency of the toilet’s suction power and refill rate.

Users also love the sleek look of the toilet that compliments all bathroom aesthetics.

The most common complaint is the toilet’s price. Users note they wish they received more bang for their buck.