The Hayward pool pump filters work to keep the water clean during the filtering process. Hayward pumps have many different functions, which are used to filter water, clean the filter and lower the water in the pool. There are two types of Hayward filters --- diatomaceous earth (D.E.), a powder that adheres to the filter inside the pump --- and sand filter. Although the filters use different media for filtering the water, they share much of the same functions.
Set the valve handle to "Filter." The filtering process moves the water from the pool, through the pump and sand or D.E. filter, then back to the pool. The filter runs two to four times a day depending on how you have the filtering timed.
Turn the valve handle to "Backwash." Backwashing is done when the pounds-per-square-inch (PSI) raises five to eight PSI above the clean reading of the pump. The clean reading is the pressure gauge reading when the pool was started up for the first time. This process removes the tiny dirt particles from the sand or D.E. filter inside the pump.
Move the valve handle to "Rinse." Rinse is used after backwashing to remove all the dirty water from the filter. The water is passed through the waste drain and out through the backwash hose.
Use the "Waste" position to lower the water level while bypassing the filter. This function is also used when vacuuming the pool water that has a large amount of debris. Bypassing the filter during vacuuming doesn't clog the skimmer, which will cause the vacuum to lose suction.
Use "Recirculate" to bypass the filter and circulate water from the pool and back without filtering the water.
Move the valve handle to "Closed" to shut down the flow of water from the filter to the pump. This should only be used when the pump is shut down.
Use "Vacuum" when cleaning the pool floor of small amounts of debris. The debris passes through the skimmer and the filter. Some Hayward filters have the vacuum function and some just use the filter function while vacuuming the pool.