The Kohler Cimarron K-31621 is a two-piece, chair-height (Comfort Height) elongated toilet. It uses 1.28 gallons per flush, fits a standard 12-inch rough-in and is WaterSense labeled. Buy it when those numbers match your bathroom. Kohler sells many other Cimarron combinations, so none of the specs below carry over to a different model number.
K-31621 specifications
From Kohler’s current specification sheet:
| Item | K-31621 |
|---|---|
| Configuration | Two-piece, elongated, Comfort Height |
| Flush | 1.28 gpf, AquaPiston canister with Revolution 360 |
| Rough-in | 12 inches |
| Rim height | 16-1/2 inches |
| Front projection | 28-15/16 inches from the finished wall |
| Trapway | 2-1/8-inch, fully glazed, exposed |
| Components | Tank K-31615 and elongated bowl K-31588 |
| Lever | Left-hand, polished chrome |
| Included | Bowl and tank. Seat and supply line sold separately |
| Warranty | Kohler one-year limited warranty |
Because the seat and supply line are extra, add them before comparing K-31621’s price with a Kohler “Complete Solution” package. Those packages include a seat, wax ring and bolts.
Measure before you buy
- Rough-in: measure from the finished wall, not the baseboard, to the center of the closet bolts. K-31621 needs 12 inches.
- Projection: almost 29 inches from the wall. Check door swing and the walkway in front of the bowl.
- Supply valve: compare where your shutoff sits with the sheet’s supply-location drawing.
- Back-to-back drains: if another toilet drains into the same stack from the other side of the wall, Kohler requires a 45-degree double wye fitting, not a double sanitary tee.
Installation and parts
A new toilet doesn’t fix a cracked flange, a soft floor or a blocked drain. Check the flange when the old toilet is off, and stop if the bowl rocks rather than overtightening the porcelain. For future repairs, record the combination, tank and bowl numbers and use Kohler’s parts lookup for K-31621. Don’t assume every Cimarron lever, canister seal or lid interchanges.
This review is based on Kohler’s documents. No unit was installed or flush-tested.