The Kohler Archer K-3551-0 is a comfort-height two-piece elongated toilet that fits the middle ground between basic utility and a more polished bath fixture. It uses a 1.28 GPF AquaPiston flush for efficient operation and leaves the seat choice open, which can be useful if you already have a preferred slow-close or bidet-compatible seat. Its exposed trapway and traditional two-piece layout keep the installation familiar for standard replacement work.
What rough-in does the Archer K-3551-0 need?
The Archer K-3551-0 is specified for a 12-inch rough-in. Measure from the finished wall to the center of the flange bolts to confirm your bathroom matches before purchase. Since this is a fairly standard two-piece layout, installation is usually straightforward when that dimension is correct.
How strong is the flush on this Archer toilet?
The AquaPiston flush is intended to provide full-performance gravity flushing while keeping water use to 1.28 gallons per flush. Its canister-style valve helps water leave the tank quickly and evenly, supporting waste removal and bowl rinse. For everyday residential use, it is positioned as a practical balance between efficiency and dependable performance.
Can I install an aftermarket seat on the Archer since one is not included?
Yes, and that flexibility is one of the advantages of this model. Because the bowl is elongated, there are many compatible seat options on the market, including soft-close seats and some bidet-seat combinations. You should still verify that the seat is designed for elongated bowls and compatible with the toilet's mounting pattern.
What is the benefit of Comfort Height on the Archer K-3551-0?
Comfort Height raises the seat to a more chair-like position, which many adults find easier on the knees and hips. That can be particularly helpful in a main bathroom used multiple times per day or in homes planning for aging-in-place. The higher bowl can feel less natural for very young children, so household needs should still be considered.
Does the Archer K-3551-0 qualify as a water-saving toilet?
Yes. At 1.28 GPF, it uses less water than the long-standing 1.6 GPF standard while still being designed as a full-size elongated toilet. Under your instructions, all 1.28 GPF models in this batch are marked WaterSense certified. That makes it a good fit for buyers who want straightforward efficiency in a traditional two-piece format.
# Kohler Archer Comfort Height Two-Piece Elongated Toilet **Model:** `K-3551-0` **Brand:** Kohler **Category:** Toilet > The Kohler Archer K-3551-0 is a comfort-height two-piece elongated toilet that fits the middle ground between basic utility and a more polished bath fixture. It uses a 1.28 GPF AquaPiston flush for efficient operation and leaves the seat choice open, which can be useful if you already have a preferred slow-close or bidet-compatible seat. Its exposed trapway and traditional two-piece layout keep the installation familiar for standard replacement work. ## Specifications | Attribute | Value | |---|---| | Product Type | two-piece | | Bowl Shape | elongated | | Gpf | 1.28 | | Flush Technology | AquaPiston | | Height Type | comfort-height | | Seat Height In | 17.5 | | Trip Lever | left-hand | | Trapway | exposed | | Rough In In | 12 | | Seat Included | No | | Color Finish | White | | Water Sense Certified | Yes | | Warranty | Limited Lifetime | ## What's Included - Two-piece toilet (tank and bowl) - Left-hand trip lever - Mounting hardware Source: https://www.jaspecs.com/kohler/toilet/k-3551-0-kohler-archer-comfort-height-two-piece-elongated-toilet/