IC40 "low salt" - flow switch replacement attempt or buy new one?

[Ryan-Cal]

My Pentair Intellichlor IC40 salt cell from 2018 is not producing chlorine. It's reading low salt even though my pool has 3800 PPM and "ideal salt" is well below that (67 degree water). I emailed Pentair and they said that cells go bad after 2-3 years. Yay. I've read other threads about replacing the flow switch and I see that generic replacements are now available for a little over half the price of Pentair.

I use the TFT test kit, including the saline test, and I'm confident in my salt measurements (not as confident with my use of the TA and CH tests).

1) Could a flow switch replacement (like this one) actually prolong the life of my cell at this point? Worth a try?
2) Anyone have experience with the generic replacements like this one? Are they just as good?
3) Does anyone have a favorite online retailer that offers recently manufactured Pentairs cheaper than the big pool stores?
4) Other advice?

I went through 3 Pentairs in the first 3 years living in my house (1 original, 1 paid replacement, 1 warranty replacement) and this one has lasted 5 years (it was a second warranty replacement).

Thanks,
Ryan

 

[JamesW]

 

[JamesW]

Replacing Bad Temperature Sensor in the Flow Switch with a Separate Sensor.​

Pentair has the temperature sensor integrated with the Flow Switch. If the temperature sensor fails Pentair expects the entire Flow Switch assembly to be replaced. The temperature sensor in the Flow Switch is a standard 10K thermistor temperature sensor which can be used in place of the one in the flow switch.

Install the thermistor in the plumbing near the cell using a water temperature probe, like the one that comes with an EasyTouch. Drill a hole in the pipe, stick in the probe, and use a hose clamp to hold it in place.[6]



Then cut the green and white wires in the flow switch. Attach the two wires from the thermistor to the green and white wires going into the cell using Scotchlok UR2 connectors so you don't have to strip the wires. Just crush the button and the wires are connected. The two green and white wires coming from the switch will be left disconnected.

Newer Cells (after 2018)have a 3 wire system. The black wire is common. Just cut the white wire, attach one wire from the thermistor to the white wire, and one to the common black wire.


Now the cell sees the water temp from the new probe and not the thermistor in the flow switch.

Pentair Intellichlor ICXX SWG - Further Reading

www.troublefreepool.com

 

[Ryan-Cal]

The flow switch wouldn't be responsible for the low salt reading, so I doubt changing it would fix your issue. There's a separate device within the cell that calculates the salinity.

Pentair Intellichlor ICXX SWG - Further Reading

www.troublefreepool.com

While cheap, generic salt cells are a gamble. The general consensus on TFP is that you get what you pay for.

Do you have automation? If not, there's several options out there if you are not married to Pentair.

Compare and Review Saltwater Chlorine Generator Prices and Features | DSP

www.discountsaltpool.com

Thanks. That's great feedback.

Yeah, sounds about right on the generic.

I do not have automation, but my Pentair power source is in good shape. If I switched, wouldn't I have to get a new power source? Thoughts on the best brand of salt cell?

Thanks again,
Ryan

 

[Ryan-Cal]

Replacing Bad Temperature Sensor in the Flow Switch with a Separate Sensor.​

Pentair has the temperature sensor integrated with the Flow Switch. If the temperature sensor fails Pentair expects the entire Flow Switch assembly to be replaced. The temperature sensor in the Flow Switch is a standard 10K thermistor temperature sensor which can be used in place of the one in the flow switch.

Install the thermistor in the plumbing near the cell using a water temperature probe, like the one that comes with an EasyTouch. Drill a hole in the pipe, stick in the probe, and use a hose clamp to hold it in place.[6]



Then cut the green and white wires in the flow switch. Attach the two wires from the thermistor to the green and white wires going into the cell using Scotchlok UR2 connectors so you don't have to strip the wires. Just crush the button and the wires are connected. The two green and white wires coming from the switch will be left disconnected.

Newer Cells (after 2018)have a 3 wire system. The black wire is common. Just cut the white wire, attach one wire from the thermistor to the white wire, and one to the common black wire.


Now the cell sees the water temp from the new probe and not the thermistor in the flow switch.

Pentair Intellichlor ICXX SWG - Further Reading

www.troublefreepool.com

Thanks so much. So, it's probably unlikely that the thermistor is causing my problem, but it's worth a last-ditch effort to see if I can revive the cell? Does that sound about right?

 

[JamesW]

So, it's probably unlikely that the thermistor is causing my problem, but it's worth a last-ditch effort to see if I can revive the cell? Does that sound about right?

The thermistor is the likely cause of the problem.

How are you testing the salinity?

Taylor K-1766 Salt Test Kit

tftestkits.net

 

[Ryan-Cal]

The thermistor is the likely cause of the problem.

How are you testing the salinity?

Taylor K-1766 Salt Test Kit

tftestkits.net

With the Taylor K-1766. It would make sense because right before it started reading low salt, it was reading high salt (even though I was barely above "ideal salt").
Thanks,
Ryan

 

[JamesW]

Cut the white wire as shown in the video and see if that helps.

 

[Ryan-Cal]

Cut the white wire as shown in the video and see if that helps.

That's great. Sounds like an easy solution if it works. If it doesn't, the temp probe replacement but be above my skill level. Thanks again.

 

[Ryan-Cal]

Amazing. I cut the white wire and it’s now showing proper saline levels.

Questions: what’s the downside of what I just did? Do I need a proper thermistor at some point? Do you recommend I replace that properly? What’s going to go wrong when the pool water temp is way off what it’s reading ?

Thanks for your help. Truly amazing.

 

[Jimrahbe]

Ryan,

When you cut the wire you disconnect the thermistor and the cell will use an internal fixed resistor.

The problem is that now your salt reading is no longer temperature compensated. This is not a problem when the water temp is mid-range but will become a problem as the water temp goes up or down.

If temperature compensation was not required, they would just use the fixed resistor.

No rush, but you need to replace the flow switch assy or do the external temp probe as outlined in the pic that JamesW posted.

Thanks,

Jim R.

 

[JamesW]

I don't think that there is a fixed resistor.

Once it ignores the temperature sensor, it just uses 77 degrees as the assumed temperature.

 

[Jimrahbe]

I don't think that there is a fixed resistor.

Once it ignores the temperature sensor, it just uses 77 degrees as the assumed temperature.

James,

I just wrongly "assumed" it used a fixed resistor to set it to 77 degrees, but what you say makes much more sense.

Thanks for the feedback,

Jim R.

 

[Ryan-Cal]

Thanks, all. I appreciate the help. Replacing the flow switch assembly seems easier than adding the external thermometer. Is it as simple as buying something like this and attaching the wires, screwing it in, and sealing it up? Amazon.com

You guys just saved me $1200. I can’t thank you enough!

 

[mknauss]

Is it as simple as buying something like this and attaching the wires, screwing it in, and sealing it up?

It is. Be careful installing it as you can bend the flow spring when turning it to install.

I installed the external thermistor with a new cell. That insures you will not have a failure later.