High Salt reading on a Pentair IC40

[Vann]

I'm looking for some help. I'm new to this whole pool thing...we just moved into our new house last week and have a question around our Pentair IC40 Chlorinator.

The chlorinator is reading high salt (excess of 4200ppm) while testing the water at our local Leslie's Pool Supply store is reading 2700ppm (2 seperate tests...different trips) which is actually low. The pool was installed 5 years ago and I'm guessing that this equipment is original from the install.

A little background, last week I took a sample of our pool water into our local Leslie Pool Supply store to be tested. The test results came back with 1600ppm and no chlorine. The IC40 on the other hand was reading 'good' salt levels (3000-4200ppm). The cell status light was blinking at this time, so I cleaned the cell using the appropriate technique. After reconnecting the cell status light stopped blinking. I then added 5 bags of salt (~17k gallon pool) and the high salt indicator has never turned off since then even though the test says 2700ppm. After the shock wore off we are now back to 0 chlorine.

Is this an indication of a bad cell? Is this a calibration issue or a issue with the test done at Leslie's?

The previous owners had a company come out and test the water back in March and the pool tested at 3000ppm and no salt was added since then other than the 5 I recently added...so I have a hard time believing the salt is really above 4200ppm. With the cell reading that high though it's not going to try and produce chlorine.

 

[JasonLion]

Welcome to TFP!

The SWG has shutdown to prevent power supply damage due to it's perception of a high salt level. It is fairly common for a SWG to falsely indicate a low salt level, when the salt level is actually normal, but is is very unusual for a SWG to falsely indicate a high salt level. The chances are excellent that the salt level actually is high, although there is still a very small chance that the SWG is wrong. It is never a good idea to add salt when the SWG says that the salt level is normal.

Five 40 lb bags of salt added to 17k gallons will raise the salt level by 1400, so it is completely plausible that the salt level used to be 3000 and is now over 4200. Likewise it is completely plausible that pool store salt tests can be wildly wrong. Incorrect pool store results are reported on the forum almost every day. Pool stores tend to use salt meters that required frequent calibration, and it is quite common for that calibration to be done vary rarely, if at all. Without calibration the meter can drift quite far from correct calibration in relatively short periods of time.

It is likely that you will only need to replace a little water to get the salt level down into a range that the SWG finds acceptable.

 

[Vann]

When draining, is it something where I lower the pool a foot...refill with fresh water...and then have to wait 24 hours to see if the sensor will stop indicating high salt?

 

[JasonLion]

Yes, that about covers it. If you have a Pentair brand automation system you can get some more detailed information from the SWG through the automation system, such as the exact salt level it is measuring (averaged over the last 24 hours). Without an automation system, you have to wait 24 hours and see if the salt indicator changes.

 

[XsAllOverIt]

Get a good salt reading to insure you are within the required range. If you are and it still states that you are high, there is a calibration technique on the Intellichlor units. I had to do it because I was in range and the unit indicated that it was low. Be cautious based off of Jason's thread to make sure that the readings are correct before calibrating, if required.

 

[Vann]

Thanks for the info...

I've got a company coming out to test the unit next week. I ran a water sample to another local pool place and they had the salt at 2800ppm. Thankfully we got a home warranty with the house that would cover replacement of the unit if they deem it unrepairable.