My old Jandy SWG reached the end of cell life, so I decided to replace everything - control panel, cell, sensor. I'm getting "no flow" messages intermittently when my pump is on low speed. If I change pump to high, system stays on. My pump is a Jandy PHPM 152 (1.5HP) pump that I installed last year. Jandy SWG specs call for min. 30 GPM. I recently cleaned my filters and find it hard to believe that system could be under 30 GPM. Old system never gave "no flow" messages.
http://www.poolspapartsplus.com/images/x/L0976A.pdf - pump performance curve
Does it take a while for new sensor to break in? Do you think I have defective sensor?