Dual-flush toilets save money on your water bill. They have two separate buttons for flushing the toilet, depending upon the waste inside. Liquid waste requires less water than solid waste. As with any other toilet, adjustments are occasionally necessary to ensure the toilet works properly. Adjusting a dual-flush toilet involves adjustments to the water level and the flush buttons. Making adjustments to the dual-flush toilet does not require removal of water from the tank. You will need to flush the toilet when testing your adjustments.
Lift the dual-flush toilet tank lid off the tank and place it upside down on a flat surface. There are two rods under the tank that connect to the push buttons. Do not bend or damage these rods.
Find the float adjustment screw between the fill valve and the flush valve. Turn the adjustment screw clockwise with a flat-head screwdriver to raise the water level to the indicator line on the inside back of the toilet tank. Turn the screw counterclockwise to lower the water level.
Place the lid back over the tank and test the flush buttons. The small button is for liquid waste, and the larger button is for solid waste. Some dual-flush toilets require pushing both buttons for solid waste. Test each button to make sure the toilet flushes properly. The small button has a small flush, while the bigger button or both buttons together flush the toilet fully.
Remove the lid from the tank and lay it flat upside down if adjustments are necessary. Loosen the plastic nut on the push-button rod with a wrench. Do not remove the nut; just loosen it enough to turn the rod on the push button.
Turn the push-button rod clockwise to lower the rod and counterclockwise to extend the rod. Only turn the rod one full turn at a time. Tighten the plastic nut and place the lid back on the tank. Test the flush operation again. Continue making adjustments as necessary.