IC40 reading low but water tests at 3400 ppm

SoonerWing

LifeTime Supporter
Jan 27, 2015
147
Tuttle/Oklahoma
#1
So I have been pouring liquid chlorine into my pool for weeks now and haven't been able to keep my chlorine up. My IC40 was showing that the salt was low so I added a bag of salt here or there (didn't have a good saltwater test kit at the time so I was relying on the IC40 to tell me when to stop) would wait a couple of days to see if it went green before adding another. I think that I added a total of 3 bags before it turned green for a couple of days then back to red. So I ordered the Taylor Sodium Chloride test kit to see where the salt actually is. The test kit was literally just delivered so I ran out and tested the water and it comes in at 3400 (I was a little afraid that it was going to be way high. I am in the process of cleaning it now so we will see if it gives me different lights here in a bit. If not and knowing that the salt content is 3400, should I try to recalibrate the current IC40 before replacing? It's not quite 2 years old.

Other readings

FC: 4
PH: 7.2 (lowered it by adding acid this morning
TA: 110
CHA: 450

I have been waiting to figure out exactly what my salt is so I can determine my next step.
 

drharris

Well-known member
Jun 29, 2016
275
Walhalla, SC
#2
I have an IC-40 (and have had major issues: Intellichlor IC40 Low Salt but reads fine). I finally learned how finicky this thing is when the season started to end. Basically, you have to clean this thing about every 2 months for the sensor to work correctly, so start with a good cleaning. Second, I'm not sure what weather there is like, but at water temps below 65 or so degrees, you can't trust the light on the IC-40. It doesn't seem to update the readings for a long time (at least 6 hours, not sure if even longer), so you may need to manually power it down/up to get it to read again when the water temp rises a bit.

Either way, definitely do not dump salt in the pool based on the light - always independently test.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,864
Bedford, TX
#3
dr,

While you are right on about the unit only updating every 12 hours and to not always trust the salt reading it provides, your idea that you have to clean the cell every two months is not at all true.

If you keep your water per the TFP guidelines inspecting your salt cell once of a year is plenty. And just because you inspect it, does not mean you have to acid clean it.

Cells get a lot of build up on the plates because of bad water chemistry, not because the cell is bad.

The main problem with the Intellichlor is its temperature sensor, which is not all that robust in my opinion. When the temperature sensor is off, or bad, it causes the salt readings to be inaccurate.

Soonerwing, there is no cell calibration for the IC40, except for very very old cells...


Here is a test, provide by JamesW, which tests the temp sensor.

Pressing and holding the “More” button launches the System Status Mode. When the lights finish scrolling, the percent lights indicate hours of usage in 1,000s. For example, if the 40% light lights, that indicates 4,000 hours.

Version 3.1 on adds the ability to determine system temperature. Pressing the “More” button after the display shows 1,000s of hours of usage, will show temperature as follows:

Lights…………….....………Temperature
No LEDs………….…..………Below 30F
40%..........................36 to 45F
40% and 60%............46 to 55F
60%..........................56 to 65F
60% and 80%............66 to 75F
80%.........................76 to 85F
80 and 100%............86 to 95F
100%.......................96 to 99F
100% blinking……..….over 99F
All LEDs blinking……...Sensor bad

The temperature sensor is a 10k thermistor. Its resistance varies based on the temperature. The way it varies is known precisely. So the box measures resistance in ohms and calculates the temperature.

If the thermistor fails in a way that’s obvious to the software, the software will ignore the thermistor and use 75 degrees F as the temperature.

When using 75 as the default temperature, the salinity will be miscalculated by the software for any water temperature other than 75 F.

Thanks,

Jim R.
 

drharris

Well-known member
Jun 29, 2016
275
Walhalla, SC
#4
While you are right on about the unit only updating every 12 hours and to not always trust the salt reading it provides, your idea that you have to clean the cell every two months is not at all true.

If you keep your water per the TFP guidelines inspecting your salt cell once of a year is plenty. And just because you inspect it, does not mean you have to acid clean it.

Cells get a lot of build up on the plates because of bad water chemistry, not because the cell is bad.
Thanks for the clarification Jim. I didn't mean to imply that the cell itself needed cleaning, but doing an acid clean seemed to help the temperature sensor work correctly in my case. Granted, I inherited some very badly balanced water, so that could have been the culprit. Or it could have been a lucky coincidence that it worked after a cleaning.
 
OP
OP
S

SoonerWing

LifeTime Supporter
Jan 27, 2015
147
Tuttle/Oklahoma
#5
dr,

While you are right on about the unit only updating every 12 hours and to not always trust the salt reading it provides, your idea that you have to clean the cell every two months is not at all true.

If you keep your water per the TFP guidelines inspecting your salt cell once of a year is plenty. And just because you inspect it, does not mean you have to acid clean it.

Cells get a lot of build up on the plates because of bad water chemistry, not because the cell is bad.

The main problem with the Intellichlor is its temperature sensor, which is not all that robust in my opinion. When the temperature sensor is off, or bad, it causes the salt readings to be inaccurate.

Soonerwing, there is no cell calibration for the IC40, except for very very old cells...


Here is a test, provide by JamesW, which tests the temp sensor.

Pressing and holding the “More” button launches the System Status Mode. When the lights finish scrolling, the percent lights indicate hours of usage in 1,000s. For example, if the 40% light lights, that indicates 4,000 hours.

Version 3.1 on adds the ability to determine system temperature. Pressing the “More” button after the display shows 1,000s of hours of usage, will show temperature as follows:

Lights…………….....………Temperature
No LEDs………….…..………Below 30F
40%..........................36 to 45F
40% and 60%............46 to 55F
60%..........................56 to 65F
60% and 80%............66 to 75F
80%.........................76 to 85F
80 and 100%............86 to 95F
100%.......................96 to 99F
100% blinking……..….over 99F
All LEDs blinking……...Sensor bad

The temperature sensor is a 10k thermistor. Its resistance varies based on the temperature. The way it varies is known precisely. So the box measures resistance in ohms and calculates the temperature.

If the thermistor fails in a way that’s obvious to the software, the software will ignore the thermistor and use 75 degrees F as the temperature.

When using 75 as the default temperature, the salinity will be miscalculated by the software for any water temperature other than 75 F.

Thanks,

Jim R.
I saw this test in another thread and decided to give it a shot but my results are very different than everyone else.

Before the tests the lights are as such

Salt Level
Low: Red

Status
Cell: Flashing Green
Flow: Solid Green

Sanitizer Output
20%, 40%, and 60% are lit

When I run the test it cycles through the lights from bottom to top then the Cell light is lit Green, the Cold Water Light is lit Red, and the Low light is lit Red and flickers for .5 a second. It stays like that for about 3 seconds then the Cold Water and Flow lights flash Red for approximaetly 1 second before everything goes back to the lights listed above.
 

JamesW

TFP Expert
Mar 2, 2011
13,044
#6
Press and hold the "More" button for a few seconds until the lights scroll. Then, note what the "Cold Water" LED shows and what percentage lights are on.

Then, quickly push the More button again and note what percentage lights light up.

If the Cold Water LED goes solid red on the first push of the button, the system has detected a problem, usually a bad temperature sensor.

What is your water temperature?
 
OP
OP
S

SoonerWing

LifeTime Supporter
Jan 27, 2015
147
Tuttle/Oklahoma
#7
Press and hold the "More" button for a few seconds until the lights scroll. Then, note what the "Cold Water" LED shows and what percentage lights are on.

Then, quickly push the More button again and note what percentage lights light up.

If the Cold Water LED goes solid red on the first push of the button, the system has detected a problem, usually a bad temperature sensor.

What is your water temperature?


Ahh, After the second push of the More button I get Low and Cold Water are both Red while Cell is Green. Then all of the sanitizer output lights flash. I guess its a bad temp sensor? Not sure the exact temperature of the water but I am guessing it is in the 60's.
 

The dog

Well-known member
Apr 17, 2017
147
sacramento CA
#8
I called Pentair on This issue. They say to take the cell apart and inspect it every 3 months. They said to clean as required. First by spraying water in it to remove any scale. If scale remains they aid to axis wash 1:5 ratio for no longer than 30 minutes.

I don't know who said to check it one a year, but that's not what they recommend. I believe it even says on the newer cells to inspect every 3 months.


Sent from my iPhone using Tapatalk
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,864
Bedford, TX
#10
I called Pentair on This issue. They say to take the cell apart and inspect it every 3 months. They said to clean as required. First by spraying water in it to remove any scale. If scale remains they aid to axis wash 1:5 ratio for no longer than 30 minutes.

I don't know who said to check it one a year, but that's not what they recommend. I believe it even says on the newer cells to inspect every 3 months.


Sent from my iPhone using Tapatalk
Hi Dog,

I'm the one that said one a year inspection, but that was based upon real world experience, not Pentair's advice... I suspect Pentair is just covering there rear with the 3 month recommendation.

It is perfectly fine with me if you want to inspect it daily, but anytime you acid wash it, you reduce the cell's life span.

I have three of these things, and have never found more than just a minute amount of build up on the plates. It could be I'm just lucky, but I doubt it.

And the official "Inspect your cell and clean it" is the same as an IT tech telling you to reboot your computer when you have already done that 10 times... :p

Occasionally it might be the answer to the problem, but my guess it that 9 times out of 10 it does nothing to solve whatever issue you are having.

Thanks,

Jim R.
 

The dog

Well-known member
Apr 17, 2017
147
sacramento CA
#11
You guys can do what you want based on your experience. I was only telling you guys what they said. I've only had my ic40 running for 2 months. I haven't opened it yet

I never said to inspect it every day.

And back to the pc thing. A cold boot is different than a reset. And yes a cold boot can help when a reset doesn't because the memory is cleared.

Take care JR


Sent from my iPhone using Tapatalk
 
Apr 17, 2017
12
Powell/OH
#12
Ahh, After the second push of the More button I get Low and Cold Water are both Red while Cell is Green. Then all of the sanitizer output lights flash. I guess its a bad temp sensor? Not sure the exact temperature of the water but I am guessing it is in the 60's.
This is what mine did last month when I opened the pool. I replaced the temp sensor and it fixed the problem.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,864
Bedford, TX
#13
You guys can do what you want based on your experience. I was only telling you guys what they said. I've only had my ic40 running for 2 months. I haven't opened it yet

I never said to inspect it every day.

And back to the pc thing. A cold boot is different than a reset. And yes a cold boot can help when a reset doesn't because the memory is cleared.

Take care JR

Sent from my iPhone using Tapatalk
Dog,

Your post was fine, I was just trying to tell the other side of the story..

Not sure what you plan to do about inspecting your cell, but if you do decide to do it every three months, please provide us with some real world feedback.
It would be interesting to see what you find and your recommendations might help others.

As I said, I could just be lucky,

Thanks for posting,

Jim R.
 

The dog

Well-known member
Apr 17, 2017
147
sacramento CA
#14
I certainly will JR. I was going to check the cell and take apart my filter at the same time. In another month.
Like you said, different things work for different people and you need to do a little experimentation on what works best for your situation.

Have a good one.


Sent from my iPhone using Tapatalk
 
OP
OP
S

SoonerWing

LifeTime Supporter
Jan 27, 2015
147
Tuttle/Oklahoma
#15
Yesterday was sunny and got up into the upper 80's and the IC40 was lit up all green and pretty. Water test this morning showed that it produced chlorine yesterday. This morning it is in the low 60's and it is not longer lit all green and pretty. I am guessing that the water temp droped over night down below the magical number. It should be another nice day today so I am interested to see if we have a repeat of yesterday. Either way my temperature sensor is on its way :D
 

JamesW

TFP Expert
Mar 2, 2011
13,044
#16
As the water warms up, the salinity calculation gets more accurate because the system is using 75F as the water temperature.

At a water temperature of 75F, the salinity should be correct.

As the water temperature passes 75F, it will begin to read the salinity as higher than actual and might end up giving a false high salt error.

I think that if you raised the salinity to about 3800, the cell will work.
 

drharris

Well-known member
Jun 29, 2016
275
Walhalla, SC
#17
I've had the recurring red low salt light before on the IC40, and I've had luck with simply getting it on a better "schedule" of testing it at the 12h interval. I cycled power on it around 11am one day, and it checked fine. Now it is probably checking at 11pm and 11am, times when the water is either still decently warm from the day or has had sun for a few hours. I suspect once June hits it will not really be a problem. Either way I think the temperature/flow sensor is probably the weakest link of these devices.
 

The dog

Well-known member
Apr 17, 2017
147
sacramento CA
#18
I agree as it jacks with the salinity level. In the am the pool is cold and reads low. Then at the end of the day it's warm and reads almost normal. My ic40 is about 200 +/- off from the Taylor test especially if I test in the am.


Sent from my iPhone using Tapatalk