CL 220 installed in 2009 and initially worked ok. This season, flow does not seem to change with control valve (CV) position. As suggested by Hayward Tech Service, I removed CV, lubricated two O-rings and replaced. However, this did not help. 3 pucks are almost gone (dissolved/eroded) in 2 days when CV is in Fully Closed position as well as in Fully Open position.
(The problem resulted in high CYA; so, have been using Cal Hypo granular chlorine.)
I'd be grateful for advise on a likely cause of the problem and how to fix it. Many thanks.