IC40 reading low salt

dethman

Member
Nov 11, 2017
12
CA
Moved from here.
Thanks guys. That makes sense it would be water temp, although I don't have a water temp sensor installed (story for another day!), I'm sure it's pretty low. Good idea on the flow switch assembly, I'll wait till it warms up a bit and check it out again.

My CYA was low (40), so I'm sure that wasn't helping with chlorine levels either.

Also, is Youtube the only way to post a video? I have a quicktime video of the test I did on the cell but I can't attach it.
Were you able to figure out the problem? My Ic40 is reading zero/low salt and not generating even at 64 degrees water temp. Wondering if the flow sensor alone would fix things or whether I'm going to need an entirely new cell.
 
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dethman

Member
Nov 11, 2017
12
CA
Where is your IC40 reading zero/low salt? On it's display or on an Easy Touch?

What to Do If Easy Touch/ScreenLogic Reports Salt Level as Zero

Please create your signature with details of your pool so we can provide you with the correct advice.
It reads low salt on the unit itself (red led), and on easy touch it reads salt level as zero even though salt level is verified both with strips and at the pool supply store.

Flow light is green and the pool temp is 64 deg today.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
16,024
Northern NJ
Probably a bad thermistor in the flow switch. You can replace the flow switch or install an external temperature probe connected to the flow switch wires.
 

dethman

Member
Nov 11, 2017
12
CA
Probably a bad thermistor in the flow switch. You can replace the flow switch or install an external temperature probe connected to the flow switch wires.
Thanks, I will look for a replacement. Out of curiosity, why would a faulty thermistor(used for temperature?) cause an erroneous salt reading?
 

dethman

Member
Nov 11, 2017
12
CA
Probably a bad thermistor in the flow switch. You can replace the flow switch or install an external temperature probe connected to the flow switch wires.
Also I have seen where some people bypass the flow switch in order to assess whether it may be faulty prior to purchasing and installing a new one. Would bypass work in this case as a diagnostic tool?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
26,617
Laughlin, NV
The Pentair flow switch has a thermistor in to determine the temperature of the water. That temperature is used in the salinity determination. If the thermistor is not reporting a correct temperature, then the salinity number can be out of range.

As your cell is new, you should be able to use this diagnostic protocol to see what the thermistor is reporting.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
16,024
Northern NJ
Also I have seen where some people bypass the flow switch in order to assess whether it may be faulty prior to purchasing and installing a new one. Would bypass work in this case as a diagnostic tool?
The flow switch has two sensors. The flow sensor is not your problem and bypassing tells you nothing.

The thermistor temperature sensor is likely your problem and you can display what it is reading this way...

How_Do_You_Display_IntelliChlor_Cell_Water_Temperature?

You could also cut the thermistor wires and test it with a multimeter as described here...

 

dethman

Member
Nov 11, 2017
12
CA
The flow switch has two sensors. The flow sensor is not your problem and bypassing tells you nothing.

The thermistor temperature sensor is likely your problem and you can display what it is reading this way...

How_Do_You_Display_IntelliChlor_Cell_Water_Temperature?

You could also cut the thermistor wires and test it with a multimeter as described here...

thanks. with your tutorial on testing the thermistor, all the LEDs flashed indicated the thermistor was bad.

i just purchased a new flow switch and installed it today, it appears to be working appropriately and i am finally getting some chlorine with a salt level at 3200ppm. Will run through the night to test.

thanks so much for your help.