Alternatives to IC-40 without changing plumbing? Or should I try fixing it?

[drharris]

I've about had it with my IC-40(s). I have to replace flow switches almost yearly or I get either the no-flow or flashing lights. I've had to replace the entire unit twice in 8 years. I'm overall fed up, but I don't know if there's a better alternative. Is there a viable replacement without having to change my plumbing? I see a bunch of ultra-cheapo options on the internet but that sounds like a bad idea when you're running an ongoing chemistry experiment with water, electricity, and chlorine gas.

Alternatively, is it worth trying to fix what I have, or should I just purchase another new one? I'm tempted, especially now that they extend the 2-year warranty even to self-installation (previously this wasn't an option). But I hate how expensive they've gotten.

My 2016 cell (bought new by the person selling us the house)replaced a 2014 cell the previous owner had let freeze one winter. In 2018, I had the flow switch replaced by a pool store due to the flashing lights and no-flow issue. One year later, it had the same symptoms so I decided to just purchase a new one, especially since there had been some major algae issues during the house purchase and the water chemistry was all out of whack by the time I took over (prior to finding TFP).

So, my 2019 cell, purchased from Amazon, worked fine, and all my water had been replaced along with the pool liner, and I had been following TFP methods so chemistry has been perfect for the most part. Exactly one year and a week later, the lights happened again, out of warranty. Since it was now 2020 and everything was shuttered, I bought an aftermarket flow switch from Amazon (non-Pentair I assume, since the wire gauge was different. It worked fine, though the flow light would stay green regardless of flow. Dangerous, so I kept the pump running 24/7. Things worked fine for the most part.

Last year, right as the major supply chain issues were happening, the 2019 cell died entirely. No lights at all. Local shop wasn't open anymore. If you could find a new IC-40, it was $1500+. On a whim, I said a prayer, re-installed the 2016 cell and wouldn't you know it just worked fine? No idea why, but I didn't question it. Of course, this year it is back to saying no salt, despite 3750+ppm and water at 74 degrees. Having learned my lesson in the past, I tried switching cells to the 2019 one again but it's still dead. Also having learned lesson in the past, I had another aftermarket flow switch (this time, OEM official part, supposedly) on hand. Did the swap, but it doesn't work either (says no flow). Don't know at this point if it's the switch or the IC-40 main board.

So... is it worth trying to either revive the completely dead 2019 cell, or to get the 2016 cell a proper flow switch? Is there a legitimate source for the pentair OEM switch? Comparing this OEM one to the cheapo aftermarket, it didn't seem much different. Or, should I just purchase new and be thankful for 2 year warranty? Or, is there a viable alternative brand I can consider switching to that won't be such a headache?

Edit: And/Or - is it possible I'm doing something completely wrong here to make all this happen? I keep my levels spot on, I've tested my TF-100 kit process with standards, I monitor often, and I generally keep my equipment running. Or are these units just this problematic with a weak link of a component that drives the whole thing?

 

[Jimrahbe]

dr,

The flow switch assembly has two parts; one is the flow switch, and the other is a thermistor that helps the cell determine the salinity of the water. The flow switch does not go bad very often, unfortunately, the thermistor does.

When the flow light is red, the cell will never work, it will never get to the point where it even tries to measure the salt. The Flashing "railroad crossing" light is normal at start up and every 12 hours as the cell is testing the salt level. But.. if you have no flow, the cell will never pass the salt tests.

My guess is that 85% of the time no flow is not the cell or the flow switch, but rather actually not having enough flow. Keep in mind that the flow switch has to be installed correctly if replaced. The mickey mouse clip connectors must cost about a penny each and they work just like it. I am always suspect of any connections on replaced flow switch assemblies. Also, it is not unusual for us to see the flow switch installed backwards by homeowners.

The Thermistors do go bad. When they do, the salt level reported by the cell is way off from the actual salt level in the pool. As a test, you can cut out the thermistor inside the flow switch assembly but cutting the Green wire. This causes the cell to use an internal resistor instead of the thermistor.

Another option, which was suggested by JamesW, and that I use, is to use an external thermistor (Just like the EasyTouch temp probe) instead of the flow switch thermistor.

Here is a diagram showing the connections.

Temp probe hack.jpg

• Jimrahbe
• Jun 11, 2020

Thanks,

Jim R.

 

[drharris]

Thanks Jim, this is great information. The actual flow should be good in this case, as it stayed red even if I increased the pump speed. I think it should be installed correctly (paddle bent toward (facing) the incoming flow). Is there a safe way to test it while powered up by depressing the flow switch gently with something? Similarly, is there a way to test whether the thermistor is actually bad before just assuming I'm in for a new assembly? Or if it shows low salt when I measure 3750 is that pretty much a guarantee it's gone?

I agree that the weak link here could be the little connectors for the replacement switch. Is there a known better way to connect them than the provided clips? I thought about soldering them together and putting hot glue around it to keep the connection water safe, but not sure if that's overkill.

I like the thermistor hack and I'm bookmarking this so I can just do that next time this happens. Do you know if it still generates chlorine even if it reports red (e.g. it's just used to indicate salt levels), or if it's used to actually control the output? I guess, would it be safe (and acceptable) to just clip the green wire if I'm checking salt levels independently on a regular basis?

 

[Jimrahbe]

dr,

The cell is King!! Whatever it "thinks" is happening is the only thing that counts.

If it just thinks the flow is low... nothing will work.

If it just thinks the salt level is too low, it will not make chlorine.

The flow switch actually has an arrow that you need to make sure is pointed in the direction of water flow. And.. You'd be surprised at the number of people that don't really know the direction water flows in their system..

As a test only, you can manually short the red and black wires coming from the cell together. This would simulate a closed flow switch. If the flow light stays red, that would be an indication that the cell itself is bad. Not sure if the flow light changes instantly or if it takes a minute or so.

You can tell if the cell is making chlorine by looking at the "cell" light. At 50% output the light will be on for about 2.5 minute and then off for about 2.5 minutes.

I bought a box of better connection clips.. Still cheap, but not as cheap as what comes in the off-brand flow switch kits.

Thanks,

Jim R.

 

[drharris]

Small update - glad I posted before reacting and just throwing it out... the wiring diagram really helps. Planning out the future thermistor replacement now.

2019 unit is still completely dead no matter what I do, but I took the 2016 one back out, pulled on the wires from the connector and sure enough the black one came out easily. Bad connection for flow switch. I cut all the connectors, restripped wires, and then soldered them together this time. Used hot glue as insulator (also hoping it keeps moisture out in case that's an issue). Flow switch worked perfectly after that. However, it still showed low salt for the next ~36 hours (despite aquachek strips showing 3750), but then after a power outage yesterday everything just decided to turn green and work.

Anyway, all is resolved for now, and I appreciate the help! Thankfully I learned the lesson last time this happened to always have trichlor pucks on hand in case these things go out. Thankfully it seems to happen more in early spring or late fall, so less risk than dead of summer!