Recalibrate IC40?

Roberd07

Member
Jun 26, 2019
24
Fort Worth Texas
My IC 40 is displaying a low salt reading (2600 ppm) via the cell red light and the system reading. I’ve tested the water with the K-1776 and verified it to be 3400 ppm. Testing for chlorine it would seem that the cell is not producing at the moment. The cell is roughly 2.5 years old and I replaced the flow switch back in January to rectify a 0 salt reading. Not sure where I should start in diagnosing. Recalibrate the cell? Reading through the forum posts I noticed some posts in regards to a bad power supply board. Not sure if it’s coincidence but after a tech support call to Pentair I am having to replace my ScreenLogic protocol adapter. It was an older unit (and older version) so I have no idea whether the recent storms (lightening strike) in the DFW area or age killed it. Any help would be appreciated.
 
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JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
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Tucson, AZ
Pool Size
16000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Would it still show a low reading if were bad? Or would it show a zero reading if it were bad?
Either or. If the thermistor is reporting a temperature that is off from actual, it can cause the salt reading to be way off. A zero reading can be a dead thermistor but it is often a bad serial communication between the EasyTouch panel and the IC.
 

Jimrahbe

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Jul 7, 2014
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R,

As Matt said above... Sounds like the thermistor inside your Flow Switch Assembly is bad.. If the cell is under warranty have Pentair fix it.. If not, it is a pretty easy DIY repair.

There is no calibration that can be done.. The original cells could be calibrated, but that has not been true for 10 years or so..

Thanks,

Jim R.
 

Jimrahbe

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Rob,

That is just now how it works... The Red and black wires go to the flow switch which has nothing to do with the salt level light. See this diagram..




When the salt level does not work the problem is generally the thermistor.. You can't "short" the thermistor and make it work. You can open the circuit by cutting either the green or white wire. This will make cell think the water temperature is about 75 degrees.. If this makes your salt level read closer to the actual salt level measured by a salt test kit, then it would confirm that the thermistor part of the flow switch assembly is bad.

The diagram shows how to use a standard temp probe as a replacement for the thermistor that is inside the Flow Switch Assembly.

Thanks,

Jim R.
 
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Roberd07

Member
Jun 26, 2019
24
Fort Worth Texas
Ok, per the link I was provided above it mentioned cutting and connecting the red and black wires coming out of the cell for a possible diagnosis. So then if I cut the green or white wire and see an increased salt reading using my ScreenLogic then that would tell me that the thermistor is bad? Correct? And just so that I’m clear I could rig up the standard temp probe as a permanent replacement for the temperature part of the flow switch?
 

Jimrahbe

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Jul 7, 2014
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Rob,

The existing temp probe is most likely for your automation system..

But that is the exact type of probe that you can add per the hack diagram above.. You can't use the existing one for both the EasyTouch and the flow switch thermistor. You will have to add a new one.. in a different place.

Keep in mind that the flow switch itself has to work for the cell to check the salt level.. Make sure you reconnect the red and black wires.

The cell only tests salt at start up and then every 12 hours..

Thanks,

Jim R.
 

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Roberd07

Member
Jun 26, 2019
24
Fort Worth Texas
Thanks for the clarification. And just to make sure I’m clear, when I cut either the white or green wire and if I see an increase in the salt level then it’s just the thermistor thats bad. But if I don’t see an increase then my flow switch is bad?
 

Jimrahbe

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Jul 7, 2014
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Rob,

Two different things that are not directly related..

The flow switch won't let the cell function if open.. This means the salt test and everything else will not work, but a bad flow switch itself will not cause an inaccurate salt reading. The Flow switch is a safety device..

The Thermistor is a resistor that changes its resistance with water temperature.. It is what the cell uses to determine the water temperature. The cell uses that info plus some current readings to determine the salinity of the pool water. If the thermistor tells the cell the wrong temperature, it makes the salt readings inaccurate..

Thanks,

Jim R.
 

Roberd07

Member
Jun 26, 2019
24
Fort Worth Texas
So I need some more guidance. I pulled the white wire from the flow switch back on the 28th and sure enough the salt indicator light on the cell went from red to green and as expected my ScreenLogic app showed a salt level of 0. After the heavy rains we received the other day in the DFW metroplex area the salt level light went back to red. I retested the salt level using the k-1776 and my level was still 3200 ppm. I didn’t worry too much about it because as mentioned above I replaced the flow switch back in January so I was able to convince the provider to warranty the switch. When I changed out the switch I once again had a salt level reading via ScreenLogic however it was only 2600 ppm. I retested the water once more time with the k-1776 and sure enough its 3200. My cell seemed to be producing some chlorine so I increased the cycle from 45% to 80% so that it could catch up. Today I tested for chlorine and I basically have none in the pool. At this point should I look at replacing the cell itself?
 

Jimrahbe

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Rob,

You are confusing many different problems...

1. The fact that the EasyTouch displays zero salt has no effect on how the cell is working.. It is just a reporting issue between the Cell and the EasyTouch.. As long at the cell's salt light is green, then that is all that matters..

2. The actual salt reading using the K-1766 is +/- 200 ppm, so it is the number to believe. The salt level the cell reports is +/- 500 ppm and is often outside this range.

3. No matter what the actual salt level is, the cell works off of what it "thinks" that salt is.. If the red salt light is on, then the cell thinks the salt is low and it will not work.

4. I always try to make the cell "happy" as long as I don't have to make the actual salt level go about 3500, or so. As an example.. If the actual salt level is 3000, but the cell thinks the salt level is 2600, then if I increase the actual salt level to 3400. then the cell will read that as about 3000.. This makes the cell happy and it will produce chlorine. If I can't make the cell happy without going too high on the actual salt, then most likely the thermistor in the flow switch is bad.. Replacing the flow switch will normally solve this issue.

5. Just because you have no chlorine in the pool does not make the cell bad. If the SWCG's "Cell" light is on, it is almost always making chlorine. Once you get algae a salt cell will never be able to make more chlorine than the algae can eat.

6. The first thing I would do is to use Liquid Chlorine and get my FC up above 5 ppm just before dark. Then do an Overnight Chlorine Loss Test or OCLT Overnight Chlorine Loss Test

Thanks,

Jim R.
 

Jimrahbe

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Jul 7, 2014
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Rob,

The salt light needs to be green before the cell light will come on.. Also, the cell light only comes on when making chlorine. So, if you have the output set to 50%, the cell light will be on for 2.5 minutes and then off for 2.5 minutes.. then on for 2.5 minutes, etc..

If your salt light is red, then you need to know what you actual salt level is.. If the actual salt is less than 3200, then I would add enough salt to bring up the actual to 3500 ppm.

Keep in mind that the cell does not continuously measure the salt level.. It only runs the salt test at start up and then every 12 hours. Make sure to turn the cell off and restart it to remeasure the salt level.

Thanks,

Jim R.
 

Roberd07

Member
Jun 26, 2019
24
Fort Worth Texas
Still fighting the issue of my IC40 cell calculating a low salt reading of 2650 and the k-1776 giving a result of 4K. As stated above I recently replaced the flow switch and it did rectify a no/zero salt reading per my system however the reading has yet to be accurate according to my k-1776 kit. My cell will work and produce chlorine as long as it thinks there is enough salt however as you can see my level is up to 4K from me adding salt to ”trick” the cell. Given the difficulty and price of finding a new IC40 I would really like to resolve this issue with out making a cell purchase. Should I continue to add salt to trick the cell or should I install a separate temp probe as mentioned above?
 

Roberd07

Member
Jun 26, 2019
24
Fort Worth Texas
Just ran the test and the cell displayed the 20% light after pressing and holding the “More” button and then it displayed the 80% and the 100% lights after pressing the ”More” button again. So am I reading the chart correctly that it‘s temp reading is the 86-95 degree range??
 
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