One of the most common problems pool owners run across when maintaining and serving their swimming pool is a leaking backwash valve. The backwash valve is the valve which is mounted on either the top or side of your filter tank and are specifically used clean sand filters or DE filters. One of the most popular filter manufactures in the world is Hayward Pool Products who also makes quite a few backwash valves. Based on the Hayward valve you have the fix varies slightly. This guide will help you determine which Hayward valve you have and then determine the proper fix for your situation.