I hope someone can help me with this. I purchased and installed a new flow switch because all of a sudden my Intellichlor IC40 went from very accurately reading the salt levels to showing 0 PPM. Per Pentair's recommendation I clean Intellichlor every two months and had cleaned it about three weeks prior to it reading 0 PPM. According to Pentair the reading of salt concentrations is a secondary function of the flow switch. And even though the flow light may be green, the salt reading function can fail. This was, and unfortunately still is my problem. Although I installed a new switch my Intellichlor is still showing 0 PPM with the flow light green. A water test shows my actual level is 3200. While waiting for the new switch to arrive, the salt readings came back but only for a few days. However during this time the chlorinator did produce chlorine as well as ever. When the reading went back to zero I installed the new switch but it still is showing zero with the flow light green. Does anyone have any idea what else may be the problem? Thanks in advance for any information you may have.