Another IC40 Low Salt Warning Issue

tucsontico

LifeTime Supporter
Mar 30, 2014
275
Tucson, AZ
My Pentair IC40 SWG suddenly started to show the red "Low Salt" warning light two days ago. I checked my salt levels via the Taylor K-1766 kit. Two tests came back with 3400 ppm, so I know the salt level is not low. I checked the plates on the SWG and they did have a small amount of scale on them so I rinsed them clean with a strong stream of water, reinstalled the SWG and started it. After the 2 minutes start-up cycle the low salt warning went out. Problem solved...not so fast!

This morning the red "Low Salt" warning light was illuminated again. I rechecked the salt levels and this time I got 3600 ppm. The flow light is lit up green and the water temperature is reporting 86ºF through the EasyTouch–which is exactly what my floating thermometer shows.

The IC40 was installed almost exactly 2 years ago and has been set on 60% since "dialing it in" after installation. I disconnect my IC40 when my water temp hits 60º so it doesn't get used for about 3-4 months out of a year. I'm at a loss on what to try next. Any suggestions will be greatly appreciated.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,018
Laughlin, NV
I suspect the thermistor in your flow switch has failed. The temperature reading on the ET is from a temp probe, not the IC.
Is the IC still under warranty?
 

tucsontico

LifeTime Supporter
Mar 30, 2014
275
Tucson, AZ
Thanks for the rapid response! I purchased the IC40 in late August 2018 off Amazon. According to Pentair website, their SWGs have a 2 year warranty when purchased alone. Looks like I'm out of luck for a warranty repair. Guess it's time to try a new flow switch/thermistor. Any issues with aftermarket vs OEM flow switches?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,018
Laughlin, NV
I have not heard of any issues. There is a hack used by @Jimrahbe to use a temperature probe to replace the thermistor in the flow switch. I will post it when I get to a computer.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,875
Central California
Might be worth 10 minutes to give Pentair a call, and another 10 if the first tech says no. You're sooooo close. You might find a sympathetic guy, as Pentair is well aware of this flow switch salt/temp sensor issue. They have some discretion. I would tell them I discovered the issue in August and only just now realized I had two years, but I'm not going to make it into heaven anyway! Once you cut into the wiring, you'll rule out that possibility, however slim.

If that doesn't work, did you install or did a contractor or electrician? If you, you might have only had a 60 day warranty anyway. If a pool contractor, he might be able to finagle a warranty repair for you, using his relationship with Pentair.
 

tucsontico

LifeTime Supporter
Mar 30, 2014
275
Tucson, AZ
I did the install myself. The Pentair website doesn't require "professional" install for 2 year warranty. You get an extra year with pro install. I'll try calling but being a holiday weekend with COVID, etc, etc, etc., not confident about reaching anyone. Thanks for the input!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,018
Laughlin, NV

 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,875
Central California
I did the install myself. The Pentair website doesn't require "professional" install for 2 year warranty.
Pentair's warranties can be a little foggy, and their policies and caveats appear on different pages of their site. If you buy a cell yourself and are able to just plug it in, you'll likely have two years. If there was a Power Center installation involved, or you bought it online, then it gets a little grey. No matter, that makes my earlier point. I do believe the support staff has some discretion (I have made use of that a couple times). Please report back with what they say about it, as others following along might be able to make use of what you learn. Good luck.
 

tucsontico

LifeTime Supporter
Mar 30, 2014
275
Tucson, AZ
The saga continues.... Today, I went out to do my daily pool check. I noticed there were NO lights illuminated on the IC-40. I began troubleshooting and discovered the IC-40 transformer fuse had blown. I replaced that fuse, reenergized the panel, and restarted my pool equipment . The IC-40 did it's two minute start up cycle with the LEDs cycling red and green. After the startup sequence, the green "Salt Level Good" light was illuminated. However, two hours later, the red "Low Salt" light was on.

I greatly appreciate all the inputs. I will be calling Pentair on Tuesday regarding the warranty. In the mean time, I've ordered a replacement flow sensor as I'm convinced the thermistor portion of the sensor has gone bad. If Pentair doesn't honor the warranty, I'll replace the sensor with the one I ordered. If Pentair honors the warranty, I'll have a spare on hand! (y)
 

dradam

LifeTime Supporter
Mar 10, 2013
199
maryland
Pentair does not require a replacement intellichlor to be installed by an installer. warranty should be valid within the specified time frame. I checked this with them this spring when I replaced mine.
 

tucsontico

LifeTime Supporter
Mar 30, 2014
275
Tucson, AZ
A little techie info for those who care:

I discovered that the thermistor built into the flow switch is a negative temperature coefficient (NTC) type. Meaning as the temp rises, the resistance drops. Evidently, the Pentair thermistor is set for 10 kOhms at 77º F. I took the bad flow sensor out of my IC40 and tested it with an multimeter. At 80ºF (room temp) it reads 9.35 kOhms. As I heated it with a hairdryer for about 30 seconds, it rapidly dropped resistance to 6.5 kOhms. So apparently it works as a NTC thermistor. However, I cannot locate anywhere the calibration specs, i.e., what is the specified resistance drop per degree of temp rise. I happened to have another 10 kOhm thermistor to test the same way. It reads about 8.9 kOhms at 80º F and dropped rapidly to 5.5 kOhms when heated the same amount of time with a hairdryer. Soooo, this long story does have an ending: Without knowing the specified resistance change/degree of the thermistor in the flow switch there is no way to tell via a multimeter test if the thermistor is bad!

UPDATE: My new flow switch arrived this morning and I tested it the same way. It gave similar results as the supposed bad one that was giving "Low Salt" warnings. However, when I installed the new flow sensor (aftermarket), the IC40 now shows a "Good Salt" green LED. Go figure! :crazy:
 

tucsontico

LifeTime Supporter
Mar 30, 2014
275
Tucson, AZ
Dirk, appreciate the info on temp sensors. However, the SWG weirdness continues! I replaced the flow sensor with an aftermarket brand. It worked fine for a day. Now the red "Low Salt" LED is back on! The SWG appears to be producing chlorine (bubbles in return water and maintaining FC level) but the "Low Salt" light remains illuminated. Water temp is 82ºF so that's not the issue. I sent an email to Pentair customer support yesterday. Nothing heard back yet. I'm at a loss for the next troubleshooting step.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,018
Laughlin, NV
The Salt light will be red and the unit still generating (Cell light green) if your salt level is below 2800 ppm but above 2600 ppm (as calculated by the SWCG). Once you drop below 2600 ppm, the salt light will be red and the cell light will be off.
 

tucsontico

LifeTime Supporter
Mar 30, 2014
275
Tucson, AZ
mknauss, appreciate the info on the IC40 salinity generation values. However, my pool salt level is 3400ppm as measured 3 days ago via the Taylor K-1766 kit. Something is still wonky in my SWG. I did notice that the start up sequence seems to take a bit longer than the "normal" 2 minute cycle. Going to call Pentair today.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,875
Central California
I ran mine for quite a while with the red salt light (because my salt was not low). Even after I got a new one out of Pentair. I figured, why not? Get some miles. Then I changed my strategy. I put the new one online and boxed up the "faulty" one while it still has some juice. It'll be my backup should the new one ever quit, until I can order and install a new-new one.