Begin repairing a Kohler toilet that won't refill by removing the tank lid, turning the shut-off valve clockwise to shut off the water and holding down the flush lever to drain the water from the tank. Use a sponge, towel or shop vac to remove any water that does not flush. Remove the hose that provides the tank with water. Loosen the lock nut located underneath the tank that holds the fill valve in place, and remove the valve.
Place the new fill valve in the tank, and tighten the lock nut to keep it in place. Adjust the float height in accordance with Kohler's instructions. The correct height is marked on the overflow tube or tank wall. Once adjusted, hook the refill tube to the overflow pipe, and re-install the water supply to the tank. Turn on the water, and fill the tank. Check for leaks around the back and base of the toilet.
Kohler offers a wide selection of toilets in both one- and two-piece designs. They come with a variety of seat shapes, including compact elongated, regular elongated and round front shapes. Kohler also offers a Comfort Height line featuring toilets that are 2 inches higher than regular toilets to make transitioning from sitting to standing easier for the user.