Pentair IC40 Red low temp light

abbytheo

Active member
May 15, 2018
25
Southern IN
I have unplugged to reset several times to no avail. Still getting the low temp light and my water is 68 degrees. When I push the more button for 3 seconds, it shows 20%, then when I press it again, the 40% and 60% lights are on. Is there any way to tell if this is a flow switch issue. This is my 2nd IC40. Pool installed in 2010, and the first SWG died in April of 2016, so this one that I bought on Amazon only has 2 years of use.
 

abbytheo

Active member
May 15, 2018
25
Southern IN
I only have the aqua check strips. They show 2100ppm, which is low, I realize, but I didn't want to add salt if the thing isn't working. When I opened the pool I only had to add 2 gallons of bleach to get the FC up to 6, where it has remained until today, and it's down to 2 now. I was waiting on the temperature to go up before I added salt. Other than that, my water chemistry is perfect and I want to keep it there.
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
17,890
Laughlin, NV
The flow switch thermistor, when it fails, typically shows low salt. But you all ready have low salt.

There is a diagnostic procedure -- Stolen from @JamesW :
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

Press and hold the "More" button until the lights scroll. A percentage light will light up. Note which one.

Then, immediately press and release the "More" button again and note which percentage lights light up.
 

abbytheo

Active member
May 15, 2018
25
Southern IN
So the flow switch won't help and I either have to buy another SWG or switch to something else? I am open to suggestions but would prefer not to have to buy a $700+ piece of equipment every two years!!!
 

JamesW

TFP Expert
Mar 2, 2011
14,490
The thermistor is in the flow switch. The cell is reading the temperature as between 46 to 55 degrees. That's why it shows low temperature.

A new flow switch would fix the problem.

You can just cut the wires going to the thermistor and the cell will default to always reading the temperature as 77 degrees.

There are 4 wires in the flow switch. Green and white go to the thermistor. Red and black go to the flow switch.


You can install an external thermistor near the cell and wire it in place of the thermistor that's in the flow switch.
 
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abbytheo

Active member
May 15, 2018
25
Southern IN
I can live with it reading 77 degrees. I can control the SWG by unplugging if the water temp is too low. However, stupid question alert: how do I know which is the thermistor wire, and if I cut it, then the thing will start generating chlorine?
 

JamesW

TFP Expert
Mar 2, 2011
14,490
The link in my previous post shows how to replace the flow switch.

There are 4 wires in the larger grey wire, red, black white and green.

You have to strip back the grey insulation and expose the 4 wires. Cut and cap the white and green wires.

You might have to cut through all of the wires to make it easier. Once you cut through the wires, strip back the insulation to expose the 4 wires, reconnect the red wires and the black wires and cap the green and white wires.

With the green and white wires disconnected, the cell will ignore the thermistor and use 77 degrees as the temperature.

This will make the cold water light turn off and the cell should begin to work as long as the salinity is high enough.

Since the temperature will not be available to the cell, the salinity reading will be a little bit off at any water temperature other than 77 degrees.

For water colder than 77degrees, the cell will underestimate the salinity. For water warmer than 77 degrees, the cell will overestimate the salinity.

You will probably have to get the salinity to about 3,500 to get the cell to read good salt.
 
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JamesW

TFP Expert
Mar 2, 2011
14,490
The wire should be plenty long enough. Just cut in the middle. See the wire in this video.

 

JamesW

TFP Expert
Mar 2, 2011
14,490
Remove the tag. The wire should not be cut. If it is, someone might have already replaced the flow switch.

Do you have a picture?
 

abbytheo

Active member
May 15, 2018
25
Southern IN
No picture...The wire was crimped there and when I went to straighten it out to cut it, I could see tiny copper wires. I tried to go ahead and cut it to splice but there wasn't enough to work with, plus my son, who is an electrician, said the red wires looked burnt...they were not bright copper wires, but dull, almost black. I would bet the unit Amazon sold me was refurbished or something??? Went ahead and got a new obe, hopefully that will take care of it. Again, thanks for your help!!!
 

JamesW

TFP Expert
Mar 2, 2011
14,490
Ok, the damaged wires could explain why it's not working. The new flow switch should get you back in business.

What is the date of manufacture on the sticker on the bottom of the cell?