I have a 6-month old Intellichlor IC40 (V2.01 built July 09) installed on my pool.

The LOW Salt light stays on and the Cell is off (no CL being produced). EasyTouch diagnosics show zero salt level.
Salt tests using new Aquacheck strips show salt level is 3840ppm. Took sample to Pool store test. Their test showed 3900ppm.
Acid washed the unit (4qts water/1qt acid) - - no fizzing - - cell was clean.
Put the IC40 back on and still have the Red LOW salt light on.

This morning I called Pentair tech support (Thursday 4/1/2010) to ask them if I should field calibrate the unit. The tech guy said that you can NOT field calibrate any IC40 after V1.6.

He asked me to acid wash the unit again with a ratio of 2qts water to 1 qt acid for 5 minutes and see if the LOW salt light goes out.

He gave me his phone extension and asked me to call him if the IC40 does not work properly after a 2nd acid washing. Pentair will send me a new IC40 (my pool builder is bankrupt so I'm on my own here).

There is an Intellichlor Field Calibration procedure that you can find if you Google the subject. According to Pentair, this procedure will not work for any IC40 after V1.6.

Hey Earl, keep us updated on this. We've got some pretty good SWG guys here that I'm sure will be along soon to comment.

so what's the question?

There is no question (yet) - - it's merely information intended for IC40 owners who may be thinking about trying to Field Calibrate thier unit. If your IC40 version is newer than V1.6, you can not field calibrate it (according to Pentair tech support).

We built our pool in May 07 and installed all Pentair equipment; spared no expense. Because we used ALL Pentair equipment our warranty was extended to 3 years. Thank goodness, because we had to replace our intelliclor cell each Spring for the first two years for the same reason you are posting. This year we have just put the cell back on the equipment after a cold winter in So California and so far so good. We only have 1 1/2 months left on our warranty; hope all stays good.
If you are still under warranty, I'd recommend letting Pentair replace the cell at their expense!

I successfully recalibrated my IC-40 last spring and it is a ver 1.9R (mfg 5/28/08). I used these instructions.

I've got a an Intellichlor IC40 that was part of the easytouch system. It was installed in Aug 2008 but I'm not sure what version it is.

The field calibration procedure doesn't work for me. I can get to step 5 but step 6 does not occur. I see no scrolling of the good, add, and low lights. The "SANTIZER OUTPUT 20% light" in comes on as described in step 7 but pressing the more button at that point does not allow cylcling through each salt level. It quickly exits the mode as if no buttons were pressed.

Multiple independant tests show my water has over 3500 ppm salt content yet the diagnostics on the easytouch show it as "very low" and the red "low" LED is lit on the intellichlor. I've been using a pool service but recently hired a new one. He's the one who brought it to my attention. He looked at the cell and said it looks like it was never used. He speculates the old pool service was just adding chlorine and never bothered investigating the SWG.

Seems I have the exact same issue with my IC40. Version 2.01, built 11/06/09 with Low Salt light on. Pool salt level is 3600ppm - 3800ppm (using Taylor test kit). I have tried to clean it twice now. The first time I cleaned it and put it back on I thought I had fixed the issue because the light went out. But after a few hours the Low Salt light came back on. So I cleaned it again and this time the Low Salt light came on right away. I keep my pool chemicals within limits very accurately and each time I cleaned the cell there was no sign of buildup. Going to call for warranty replacement today.

I spoke with the tech at Pentair and this is what he told me. The cell reads 3400 ppm at 77 degrees F if the salt level is at 3400 ppm. As the temperature starts to drop in the pool, mine is down to 68 degrees F, the cell loses 200 ppm for each 5 degrees F. So in my case I have around 3600 ppm salt and the temperature is 68 degrees F so 77 - 68 = 9 degrees. So then you subtract 200 ppm for each 5 degrees below 77 degrees. In my case you get about 400 ppm drop from 3600 ppm or about 3200 ppm. In other words, the cell thinks it only has 3200 ppm salt. The red led is supposed to go on below 2800 ppm. I am sceptical but am going to go ahead and add salt as the tech advised me to do. He also said that he would not use the cell in lower temperatures for these reasons and advised me to turn the cell off when the temperature gets lower and just add chlorine. He said salt cells are not designed to be used in low temperatures. He said that a gallon of chlorine should last about a month in the cooler weather.

Does all this sound right or is he pulling my leg?

No, he's telling you the truth. The "salt sensor" really measures the conductivity of the water. As the temp drops, so does the conductivity. So there may be the correct amount of salt in the pool, but the IC-40 "thinks" there is less. I know when my pool was at 80 degrees, my salt read 3100 on the Easytouch box. When i closed it yesterday, the temp was 55 degrees the salt read 2000. The salt didnt go anywhere, but the sensor measured lower conductivity due to the low temp. In practice, SWCG wont operate much below 55 degrees. It varies based on make and model, but low to mid 50's is the lower limit.

Sounds consistent with what we have been hearing, and I would avoid adding too much salt so that you are not trying to reduce salt levels when the warmer temps come back around. Using liquid chlorine for now would be just fine.

Maybe a topic for the deep end, but it sure would be nice to know the relationship between temperature, conductivity and ppm salt (on a graph). My problem is the unit is under warranty which will just run out about the time the temperature comes back up in the Spring. That would be a great time to find out my SWG is caput. I think I will increase the salt content just enough to rule out the conductivity reading as being the issue here.

Lots of variables when testing salt concentrations including temperature. Being 400 parts per million off is pretty darn close.

i just needed to chime in here. this is a great post with EXCELLENT information in regards to SWG's. my water temperature has been fluctuating considerably with cool night and warm afternoons and i noticed that my IC40 had varying salt levels. we had a big rain two weekends ago so i checked the salt level as that tends to change the salt levels. so my easytouch said my salt was down to 3000 ppm so i added a bag of salt. then 3 days later it was up to 3300 ppm and then the following day after it was cool and cloudy, it dropped back down to 3000 ppm. a head scratcher to say the least. so i was concerned that i was having an issue with my SWG so i added another bag of salt (which i should have tested with strips first) and the very same thing happened again. i hopped onto this forum, found this post and it answered all of my questions. i subsequently tested with strips and as of today, my SWG with the water temp at 62 degrees indicates 3050 PPM of salt but the strips say 3900 PPM which is in range of where it should be. my SWG still is putting out chlorine and as scott said to my recent post that the the SWG's performance will begin to decline at 55 degrees. so once i hit that level i will begin adding bleach to keep the chlorine level where it should be.

so in a nutshell, my PB never mentioned this to me during the start up process last winter nor do i recall reading any of this information above in the owners manual for the IC40.

Just a big THANK YOU to the members here at TFP for saving my valuable time and perhaps from some potential headaches!

No problem... yea, I was not told either and was thinking mine was broken. I now have 4000 ppm and water temperature of 67 and I do not show "Low Salt" on the SWG. I will also shut the SWG down at some point and start adding bleach. Beauty of the winter is FC drops more slowly so you won't have to add so much and can check less often.

Agreed. all of my lights are still green on my SWG. hopefully that will last a bit longer!

thanks again!

At least on intellichlor, the salt reading varies 200ppm per 5 degrees water change away from 77 degrees.

Can anyone answer the first question in this thread? My ic40 was working fine until I washed the filter this weekend. From that point on it reads zero salt (just as first posting). I acid washed. No difference. Actual salt reading 3500 (at neighborhood pool store). Also ic40 is not producing chlorine. I suppose the problems are related.

What version is your cell? What status does the flow light indicate?

The back says version: ICV19R. Date 01-16-09
The flow light indicator is red
The salt status indicators are showing the following flashing sequence: yellow-red-yellow-off repeat
The cell indicator light is off
Remaining indicator lights (power and life) are green, and the chlorine output light is on at 100% (I set it to superchlorinate).

Although the flow indicator is red I have a perfectly fine flow (I back-washed the paper filter cartridge last Sunday, cleared the baskets) I can see a strong flow in my skimmer basket and in the speed of the sanitizer/robot.