The backwash valve reverses the flow of water through the filter, allowing the dirt that has been trapped in the filter to flow out the back. As the backwash water leaves the tank, the dirty water is released out of the waste port of the valve, which may be connected to a pipe or discharge hose. Backwash valves are either a push pull or multiport valve attached to the filter, used to switch the water direction in one easy movement. For a push-pull valve, raise the valve (down position is normal operation; up is backwash operation). The multi-port valve will have labels.

These valves are wear items, and from time to time will require repair or replacement. Jandy, Hayward, and Pentair all have their own models of these valves. PoolDocx PCC-R certified technicians will help you diagnose any problems with your Backwash valve.