I am on my second Pentair Intellichlor IC40 SWG. Really like it. Has performed very well. First one lasted about 5 years. Second one has a year+ on it. The pool is in North Florida. This year I decided to turn off the IC40 for the Winter months to save wear and tear on the cell and also due to slowly raising Cl levels due to low sun and no use. It was "disabled" in the control system but left plugged in. All was fine for 2 months. Tested pool chemistry a few times and Cl level was slowly decreasing as expected and I was ready to use some liquid chlorine/bleach if needed. Needed to drain some from the pool a few times due to heavy rain and eventually added some salt to keep the level up. All was good, I constantly deal with rising pH (7.6 to 8.2)(due to waterfall and SWG) and add Muriatic acid when needed. Seeing swimming season on the horizon (sorry for all you Northern pool owners, I was once one too) I was getting everything cleaned up and balanced, Cl was 4-6 ppm and other parameters nominal except I knew I needed another bag of salt and stabilizer. I do my own testing but also will have the local pool store run a test. I did that about 2 weeks ago for confirmation and then added the bag of salt and 7 lbs of stabilizer. Today I ran my test and free Cl was at 20ppm! Nothing had changed other than the salt and stabilizer addition and cleaning the pool filter cartridge (using only water) which involved energizing and de-energizing the pool equipment a couple of times. The IC40 still showed as disabled and in any case was set for only 20%. All lights on the IC40 showed "green" and normal (other than a few weeks ago when "low salt" was indicated). So, any thoughts? Salt is salt and stabilizer is stabilzer and acid is acid...no chlorine in any of those (well, techincally there is Cl in the salt but it is bound to the Na until it goes through the SWG). Did my IC40 turn itself ON? Even if it had, it is set to such a low "ON time" (20%) I wouldn't think that it could build up that much free Cl in a short period. Anyone know if this is a known possible malfunction of the IC40?