Verdict

The Kohler Highline Arc K-78279 is a Complete Solution two-piece elongated toilet rated at 1.28 gpf. It should be judged as that exact configuration, not as evidence about the broader Highline family.

Kohler’s Highline catalog includes 10-, 12-, and 14-inch rough-ins, several flush rates, round and elongated bowls, and multiple heights. Verify K-78279’s current page, finish suffix, rough-in, height, projection, and included components. Measure from the finished wall to the closet-bolt center and check door, vanity, and supply clearance.

Documented K-78279 package

The current specification lists a 12-inch rough-in, 16-1/2-inch rim height, 29-9/16-inch projection, 2-1/8-inch glazed trapway, and Class Five canister flush. Kohler says the Complete Solution package includes bowl, tank, seat, wax ring, and installation hardware; the supply line is sold separately.

The sheet calls for three-bolt quick-connect installation and a 45-degree double wye for applicable back-to-back installations rather than a double sanitary tee. That drainage note is worth giving the plumber before replacing two toilets on a shared branch.

The toilet cannot correct a broken flange, obstructed drain, vent issue, or uneven floor. Inspect those conditions before setting the bowl. Keep the carton label and tank/bowl markings because Kohler’s service-parts route is model-specific.

Sources

Research limits

We did not install or flush-test K-78279. Verify current specification and installation documents for the exact suffix.