IC40 Failure Not producing chlorine


New member
Aug 4, 2018
I am at the point, that I think my cell is dead...but just in case, I am looking for alternative ideas.

FC 3
pH 7.6
TA 90
CH 550
CYA 75
Salt 3600

The flow light is green, the cell status is green, the cell output led is correct for what I have it set for. My typical output is around 12-14% to maintain FC 5ppm. At 30% today, I lost 1ppm FC. If I turn the cell up to 100%, it is producing chlorine. I just replaced the flow switch, and that didn't fix anything. I attempted to clean it this weekend, but the plates looked clean, and there were no bubbles from the acid mix.

The current chlorine levels are from me shocking it this weekend.

This system is about 3 years old, I have gone through 2 flow switches and am on my 2nd cell. This was all replaced under warranty. Is there something that I can check or look at, or do differently?


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

In most cases, when the cell light is on, the cell is making chlorine..

At 100% the cell does not make any more chlorine than it does at 10%.. It just makes it for a longer period of time.

Since the cell is only 3 years old it should not be dead already..

I suspect that you have algae, even if you can't see it yet.

I suggest that you do an Overnight Chlorine Loss Test or OCLT.. Overnight Chlorine Loss Test

I suspect that you will fail the test, but there is only one way to find out.


Jim R.
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