Pentair Intellichlor IC40 Flashing Salt Lights and Red Flow Light


New member
May 4, 2019
Austin, Texas
My IC40 SWG recently stopped producing chlorine. Even though the salt is within the proper range (~3200) and the flow is sufficient, the low/high salt lights are flashing, and the flow light is red. Every once in a while, without my changing anything, the lights all turn green and the unit starts making chlorine as it's supposed to. But then it goes back to the state I initially described.

My local pool shop thinks I need to replace the flow switch. I'd rather not incur that expense unless I'm sure that's the problem.

I'd welcome any wisdom you may have.



Well-known member
Jul 14, 2014
New York
I have the same issue. Issue started after water temp rose above 80 degrees for the first time this year. Only change this year is that I had my cell cleaned for the first time. (Seasonal pool used for 3-seasons). I called Pentair and they are sending me a new Flow switch under warranty.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

If you have a good flow of water coming back to your pool, then your flow switch is bad.. If the flow switch is bad, the cell will never do the salt tests so you can ignore them for now..

A flow switch costs about $100 bucks and is an easy DIY repair..


Jim R.
  • Like
Reactions: djc1603