How can I bypass a Pentair Intellichlor Temperature Sensor

May 11, 2012
31
Danville, IN
I have a Pentair Intellichlor (IC-40) SWG that indicates under 4000 hrs used. Yesterday, the SWG stopped working - with the Cell light going RED after the two minute starting cycle. The last two times this happened (over the last 3 seasons), replacing the flow/temp switch corrected the issue. Now I have the same problem again and I'm tired of replacing flow switches. Does anyone know how I can bypass the temp sensor so the cell will keep working even if water temperature is too low? I'm a big boy and can read a thermometer - I know I can't run the SWG below 65 degrees or so. Thanks for any help you can provide!
 
dk,

If you just cut the wires going to the thermister (not the flow switch) the cell will think the temperature is a constant 72 degrees.

The problem I see is that if the thermister is not working, it may make your salt reading so far off that the cell will always show low salt, even when the actual salt level is very high.

I modified my system per instructions by JamesW.. I basically bought a standard 10 K thermister and mounted it in the plumbing, just like my EasyTouch temp prob. I then disconnected the flow switch thermister from the cell and connected the external thermister.. That was about a year ago and so far it has been working great. The down side is when you take the cell out and want to take it away from the equipment pad, you need to also take the external temp probe out of the plumbing...

Thanks,

Jim R.
 
Thanks for much for your quick and helpful response! I went out, cut the green & white wires, and it's producing chlorine - on one of the hottest days this year! I don't know what it is with these sensors, but they don't seem very well made. I'm going to try to get as much life as I can from this cell and then I think I'm switching to CircuPool or PureLine SWG. At least their warranties are much friendlier to the DIYer. Thanks again!
 
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Yes, running about 3400 ppm right now. I'll monitor, but if the cell thinks water temp is a constant 72 degrees - shouldn't it calculate salinity based on that value? How big of an impact would it be if the water temp is 82 degrees? I'm sure the salinity will be different, but is it enough to cause issues with producing chlorine?
 
If the cell light is coming on, that indicates that the cell is underperforming. That could be from low salinity or a failed cell or scale in the cell.

The temperature would be relevant if it was reading lower than actual because that would make the salinity read higher than actual.

If the salinity was too low, but the cell thought that the salinity was ok, the cell could underperform.

How are you testing the salinity?

What is the date on the bottom sticker?
 
Using fresh test strips - 03/2019. Still, I wouldn't expect the SWG to indicate the salt level is perfectly fine one day and then totally shutdown the next. So far it has accurately indicated if the salt is too low or too high compared with my test strips. This was working fine and then suddenly the cell light is solid RED and it won't even indicate a salt level. Each time that has happened, replacing the flow/temp switch has corrected the issue.
 
I recommend the K-1766 salt test kit for best accuracy. You need to be really sure about the salinity.

Check the cell for scale and clean only if necessary.

I would do an external temperature sensor. Pentair 520272. Mount the temperature sensor in the pipe near the cell by drilling a hole and clamping the sensor in place. Then wire it to the green and white wires going to the cell.

How old is the cell?
 
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Can you comment on the color of the wires from the new sensor. Which to green and which to white or does it not matter ?

Thanks.
 
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dk,

If you just cut the wires going to the thermister (not the flow switch) the cell will think the temperature is a constant 72 degrees.

The problem I see is that if the thermister is not working, it may make your salt reading so far off that the cell will always show low salt, even when the actual salt level is very high.

I modified my system per instructions by JamesW.. I basically bought a standard 10 K thermister and mounted it in the plumbing, just like my EasyTouch temp prob. I then disconnected the flow switch thermister from the cell and connected the external thermister.. That was about a year ago and so far it has been working great. The down side is when you take the cell out and want to take it away from the equipment pad, you need to also take the external temp probe out of the plumbing...

Thanks,

Jim R.
dk,

If you just cut the wires going to the thermister (not the flow switch) the cell will think the temperature is a constant 72 degrees.

The problem I see is that if the thermister is not working, it may make your salt reading so far off that the cell will always show low salt, even when the actual salt level is very high.

I modified my system per instructions by JamesW.. I basically bought a standard 10 K thermister and mounted it in the plumbing, just like my EasyTouch temp prob. I then disconnected the flow switch thermister from the cell and connected the external thermister.. That was about a year ago and so far it has been working great. The down side is when you take the cell out and want to take it away from the equipment pad, you need to also take the external temp probe out of the plumbing...

Thanks,

Jim R.

I did the same but put the temp probe in the other end of the SWG since there was room for it, so it all comes out together when removing for winter.

The thermistor built in to the flow switch was giving bad values causing salt water readings to assume 77F temp and thus being way off when not 77. When warmer it didn’t matter but cooler, refuses to create chlorine.
 

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