Not to be confused with the toilet flushing handle, the flush valve is actually inside the tank! The flush valve moves water from the tank into the bowl after the flushing action has occurred. Flush valves can be complicated parts however, as they range in size from two to four inches and have various shapes to fit in with the rest of the toilet mechanics. However, many plumbers argue that the larger the valve the better as they move more water quicker, causing the flush cycle to be enhanced.

Flush valves come in a variety of styles and sizes, with the common categories including standard valves, 3-inch valves, tower-style valves, 4-inch vales, and dual-flush valves. These valves offer a variety of options like full/half flushes, 360-degree bowl refilling, speed flushing, and reduced water refill. The flush valve interacts closest with the refill tube, chain, overflow tube, and flapper. The parts move in one system, starting with the refill tube, then to the overflow tube, flapped, and then flush valve and ball. All of the flush valve parts are connected to the flush lever with a chain.