American Standard H2Option Dual Flush 1.28 gpf/4.8 Lpf and 0.92 gpf/3.5 Lpf 12-Inch Rough Tank - AMS-4133A218

Tank only. The 4133A218 is the rough tank half of the H2Option dual flush toilet, sold on its own for a replacement or a build-out where the bowl is already on site. It ships as vitreous china with the chrome plated top mounted push button actuator that runs the dual flush. You still need the matching H2Option bowl, the tank-to-bowl hardware, a supply line and a wax ring to complete a working fixture.

The H2Option dual flush tank is built for a 305 mm (12 inch) rough-in, which is the standard spacing on most North American installs. Measure from the finished wall to the center of the closet flange bolts. If that measurement is 12 inches you are set; at 10 or 14 inches this tank and its matching bowl will not sit correctly against the wall and you need a bowl rough-in that matches what is in the floor. The rough-in is set by the bowl, so confirm the bowl you are pairing is also the 12 inch version.

The H2Option dual flush meets EPA WaterSense criteria, and it is MaP PREMIUM listed. WaterSense is what most municipal and utility rebate programs key off, so it is the line item a procurement or facilities buyer needs on the submittal. MaP PREMIUM is the separate bulk removal benchmark, which matters when a spec calls for flush performance and not just water volume. Note the rebate applies to the complete fixture, so the bowl you pair with this tank has to be the WaterSense listed H2Option bowl for the pairing to hold.

Replacing the tank alone makes sense when the bowl is sound and the china is cracked, the trip lever or actuator is shot, or the tank was damaged in a turn. The 4133A218 is the H2Option dual flush tank, and it only performs to its rated 1.28 and 0.92 gpf flushes on the H2Option bowl it was engineered against, since the flush volume and the bowl's trapway are matched as a pair. Putting this tank on an unrelated bowl gives you a fitting that bolts up but flush performance nobody tested. If the bowl is also going, buy the complete fixture.

Two flush volumes off one actuator: a full flush at 1.28 gpf (4.8 Lpf) for solids and a partial flush at 0.92 gpf (3.5 Lpf) for liquids. The full flush alone meets the 1.28 gpf ceiling that most water conservation ordinances and rebate programs are written around, so the partial flush is savings on top of an already compliant fixture. For a property manager metering a multi-family building, that is the number that drives the payback against an older 1.6 or 3.5 gpf tank.

Two vitreous china colors: White, ordered as 4133A218.020, and Bone, ordered as 4133A218.021. The suffix is the color code, and it has to match the bowl's suffix or the two pieces will not tone together. On a fleet of units where some fixtures are already Bone, order by the .021 suffix rather than by the description.

The tank measures 18.875 x 16.5 x 9.625 inches. In a half bath with a low sill, a shelf, or a corner alcove, the height figure is the one that decides it, so measure from the top of the bowl's tank shelf up rather than from the floor. The tank weighs 29.928 lb on its own, which is a one-person carry but worth knowing before a stair job or a multi-unit turn.

American Standard classes the H2Option as a residential fixture. That is the right call for single-family, apartments, condos and hotel guest rooms, where a dual flush with a push button actuator earns its water savings. For a high-traffic public restroom, a school, or an airport concourse, spec a commercial flushometer bowl and valve instead. Those carry the cycle life and the vandal resistance that a china tank with a top mounted push button does not.

The lever is gone. The H2Option puts a chrome plated push button on top of the tank lid, one side for the 1.28 gpf full flush and one for the 0.92 gpf partial. Two practical consequences: the lid is not interchangeable with a standard American Standard lid, because the actuator passes through it, and the user has to make a choice at each flush for the savings to be real. On a rental turn that is worth a line on the move-in sheet. If tenants will not learn it, a single flush 1.28 gpf tank gets you the same guaranteed volume with nothing to explain.

The tank arrives as china with the dual flush valve and push button actuator. Plan on the tank-to-bowl bolt and gasket kit, a closet supply riser with a 7/8 inch ballcock nut at the tank end, an angle stop if the existing one is old, a wax ring or waxless seal, and closet bolts for the flange. Match the color suffix to the bowl, .020 for White or .021 for Bone. Nothing about the tank itself changes those items, but forgetting the supply riser is what sends people back to the counter.