Description

The Hayward ECX4077B1 is the genuine replacement check valve used across a wide span of Hayward filters: Star-Clear and Easy-Clear cartridge filters, Perflex extended cycle DE filters, ASL filters and ReGenX grid element DE filters.

What it does

The check valve sits in the filter plumbing and only allows flow in one direction. On a DE filter that is what keeps the powder in the tank when the pump switches off. Without a working valve, water and media drift backwards through the filter and land in the pool, so every startup is followed by a cloud of DE on the floor.

When to replace it

If you see DE in the pool after the pump cycles off, or the filter loses its charge between runs, the check valve is the usual cause. It is an inexpensive part and a straightforward swap, so it is worth changing before pulling grids or elements to look for tears.