Cbach, as I stated in my post above, I just went through the same thing. A red salt light and a 0 PPM reading one day, when the day before everything was fine. What I didn't mention, I also tried the change the flow switch fix. It didn't work. Why Pentair mentions this as a fix for salt reading problems I have no idea. The flow switch has NOTHING, I repeat, NOTHING to do with the salt readings the SWG generates, as I discovered later. After I wasted $75.00 for a flow switch I didn't need. This switch has ONE, and only ONE function, to measure the flow rate entering the SWG. That's it. If your flow light is green the switch is fine. If the flow switch fails what you would see is a red flow light, a red salt light and no green cell light. If the SWG thinks it's not getting sufficient flow it will not generate chlorine regardless of how much salt there is. The salt reading is generated by the cell itself. It's a measure of the electrical resistance detected between the fins of the cell. The flow switch has nothing to do with this. So, if all I've said is true, then why does it seem that changing the flow switch fixed Gobblerhuntr's problem you ask? It didn't, I gaurntee it. When my readings first failed, a couple of days after I ordered the flow swithch, they started working again and were still working when the switch arrived. So I figured I'd wait and see what happens before I did anything. Well about a week later the readings went to zero again, the red salt light came on, and the flow light was green, just like before. That's when I changed the switch and reinstalled the SWG. In a properly operating IC40, when you first turn it on, the red and green salt lights will alternate back and forth for a few minutes until the cell establishes a reading. If all is well the green salt light will stay lit, and after about 5 minutes the salt reading will be displayed.It's normal to see a 0 PPM for a while after the cell is turned on and the salt light turns green. The red salt light stayed lit on mine with a green flow light. Needless to say my readings stayed at 0 PPM. Let me correct something I said. If the red flow light is on, the cell does not produce chlorine OR a salt reading and the red salt light will be lit. That's the only way the flow switch influences the salt reading. A red salt light has nothing to do with the flow switch if the flow light is green. If cleaning your cell doesn't fix your salt reading problem and your flow light is green, all the flow switches in the world won't fix it[/QUO
Looks as if you have done your research and I thank you for sharing. I understood that there was a temp sensor in the flow switch that had something to do with your salt calculation. As I said earlier the switch or something I did installing it seemed to fix my problem. My salt readings match between my drip test and my EasyTouch. It may quit tomorrow but for now it is working. Who knows the connection between the SWG could have not been made good and it made better after I changed the switch. I did have it off and on for cleaning before the switch change though. I definitely understand the electrical workings of the SWG, but I can't figure out why it is working and that bothers me. My engineering mind will not let me let it rest. Any further knowledge you have I would appreciate you sharing. One more thing, all my lights were green except the low salt light. That confuses me more after reading your post.