Our office received a phone call from a Carmel Valley homeowner who was having a problem with their San Diego area swimming pool. They were noticing D.E. (diatomaceous earth) in the bottom of their swimming pool in the mornings. The swimming pool has a raised attached spa which seemed to be draining back into the pool. While inspecting the pool filter we turned off the pool equipment, inspected the 2 inch Jandy swing check valve and noticed backpressure pushing dirt and D.E. back through the pump. This was causing the D.E. and other debris to flow back into the pool. Water was also flowing back through the 1 inch spring check valve on the spa bypass which allowed the spa to slowly drain back into the pool.
We inspected the Pentair 2 inch swing check valve and noticed the check valve flapper was swelled and that the spring hinge no longer had full movement and no longer sealed properly.
The check valve cover was removed and replaced with the Pentair swing Check Valve Replacement Kit which included a new lid o-ring. We lubed the lid o-ring and attached the replacement lid and flapper taking care not to overtighten the screws. Then we replaced the spa bypass check valve. After loosening the unions, we removed the faulty spring check mechanism and installed a new spring check valve with new o-rings (National Diversified Sales Inc.). The pool equipment was restarted and checked for leaks. The pool problems were fixed.