Intellichlor 40 , only a few years old. All lights are green except the Cell Light. Salt level light is green on the Intellichlor and by my testing. Flow light is green. When I bump up the % chlorine production, the cell light comes on, but then the next time I check it, the cell light is off again. I bump it up one more % and the cell light turns back on. I just don't remember seeing this before. We've had the same type of SWG since the pool was built in 2011. Not sure how to trouble shoot the Intellichlor. Can someone help?