Hayward Industries, Inc., manufactures a wide range of pool-maintenance products including filters. Whether you're using a Hayward cartridge, D.E. (Diatomaceous Earth) or sand filter for pool water filtration, eventually you must drain the filter for cleaning or winterizing purposes. Hayward filters feature a drainpipe with either a drain plug, referred to interchangeably as a drain cap, or a drain valve. The pipe and cap models are threaded. As a result, you need only unscrew the cap to remove it from the pipe.
Turn off your pool's pump.
Access your Hayward filter and prep it for drainage by closing all valves or discharge and suction lines that would allow water to flow from the pool into the filter during draining. Open the air-relief valve. If your filter has a handle, grasp it and pump up and down several times.
Locate the drainpipe on your Hayward pool filter near the base of the filter.
Put on your grip-style gloves and grasp the drain cap. Turn the cap counterclockwise to loosen it and pull it from the pipe. If the cap won't loosen, turn the cap carefully with a wrench.