IC-40 SWG Cold Light RED_Can I "Eliminate" Thermistor?

mmcwhorter

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Jul 13, 2015
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Huntingtown, MD
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Pentair Intellichlor IC-40
Last year at startup, I had some difficulty with my IC-40 telling me the salt level was low and/or the water was too cold. I measured the SALT and it was 3200 (I have the TFT Salt Measurement Kit, very handy....)....At the time, I assumed the flow switch was going bad. Ultimately, the unit did produce CL all year long with SALT = 3600 and of course temps in the 75+ range. , so no replacement was attempted.....and at closing last fall I did a very light 20% acid/80% water cleaning before stowing the IC-40 for the winter.

Yesterday I installed my IC-40 and it ran seemingly OK for about one hour, during which time it reported the salt level was HIGH (Blinking GREEN SALT indicator), then ALL lights went off except for the COLD WATER RED indicator, which stayed solid RED. I ran the spa heater for an hour and the water went from +64F to +80F....RED COLD light stayed on. Having looked at similar issue threads on the TFP site, I purchased an aftermarket "flow sensor", which I believe should solve the problem. But it won't be here for a week. Very easy to replace.

In the meantime...I read some threads indicating that if you eliminate the connection to the 10K thermistor on the Flow Switch, it will "trick" the unit into thinking the Cold Water problem is solved....here is one that is most concise:
IC40 cold water light on but water is 86 degrees

So, I interpret this thread to tell me that: if I just disconnect (cut) the Green /White wires coming from the flow switch, this will disable the COLD water sensor and at least allow my unit to operate until the flow switch is replaced..... YES?

This thread also mentions IC-40 Version 3.1 for indicating Water Temp by pressing/holding the MORE button....my unit must be pre-3.1 as it will not go into the secondary measurement mode indicating the measured water temperature.

I was surprised at the variance in prices from $15 to more than $150 for this little flow sensor. That seems crazy....I assume and hope the aftermarket replacement unit will work the same as the expensive one.
 
Last year at startup, I had some difficulty with my IC-40 telling me the salt level was low and/or the water was too cold. I measured the SALT and it was 3200 (I have the TFT Salt Measurement Kit, very handy....)....At the time, I assumed the flow switch was going bad. Ultimately, the unit did produce CL all year long with SALT = 3600 and of course temps in the 75+ range. , so no replacement was attempted.....and at closing last fall I did a very light 20% acid/80% water cleaning before stowing the IC-40 for the winter.

Yesterday I installed my IC-40 and it ran seemingly OK for about one hour, during which time it reported the salt level was HIGH (Blinking GREEN SALT indicator), then ALL lights went off except for the COLD WATER RED indicator, which stayed solid RED. I ran the spa heater for an hour and the water went from +64F to +80F....RED COLD light stayed on. Having looked at similar issue threads on the TFP site, I purchased an aftermarket "flow sensor", which I believe should solve the problem. But it won't be here for a week. Very easy to replace.

In the meantime...I read some threads indicating that if you eliminate the connection to the 10K thermistor on the Flow Switch, it will "trick" the unit into thinking the Cold Water problem is solved....here is one that is most concise:
IC40 cold water light on but water is 86 degrees

So, I interpret this thread to tell me that: if I just disconnect (cut) the Green /White wires coming from the flow switch, this will disable the COLD water sensor and at least allow my unit to operate until the flow switch is replaced..... YES?

This thread also mentions IC-40 Version 3.1 for indicating Water Temp by pressing/holding the MORE button....my unit must be pre-3.1 as it will not go into the secondary measurement mode indicating the measured water temperature.

I was surprised at the variance in prices from $15 to more than $150 for this little flow sensor. That seems crazy....I assume and hope the aftermarket replacement unit will work the same as the expensive one.
How old is the cell? You know about the recommendation to never clean the cell with acid?
 
Mark,

Yes you can remove the thermistor from the circuit... When you do, the cell will use a fixed resistor inside the cell itself.. The problem is the thermistor is used to 'calibrate' the reported salt level based on water temp.. With the thermistor removed this will not happen.. Not a big deal, as long as you have a way to measure the actual salt level in your pool.

Does your cell have a 3-wire or 4-wire flow switch?? The newer cells have a 3-wire switch.

You can replace a 4-wire with a 3-wire, but you can't replace a 3-wire with a 4-wire flow switch.

How old is the cell ??

Thanks,

Jim R.
 
Thank you for the reply:

Just looked up the date I bought it...I was shocked to find out I bought it in 2016....so this will be the tenth season coming up. When pressing / holding the MORE button, the lights indicated 60% cell life used.

I'll have to go check on the three vs. four wire question, and it's raining hard right now....stand by.

I realize it may soon be time to buy a new IC-40, and I have been happy with the unit, so no reason to change.

Question: If I buy a brand new IC-40....I assume (and hope) it's a plug-and-play replacement installation, meaning BOTH A) the exact size between old/new units is the same, and B) the 4-pin connector to the power supply box is EXACTLY the same interface/voltages....etc... I can't imaging why Pentair would change that, but stranger things have happened. :(
 
Just looked up the date I bought it...I was shocked to find out I bought it in 2016....so this will be the tenth season coming up.
Yesterday there were still some IC40s left with the preseason sale at $1050. Today they are all $1400.

I would have told you to grab one yesterday with or without a problem at 10 years old because the new models are out and what's left of the IC40s will never be $1050 again. :(

The new IC plus 40 is going for $1509 online.
 
Found this on eBay....$780....But I am wondering if it is a genuine Pentair replacement.....because the Pentair logo is not posted on the pic.
Weasel-worded.


I'll be looking at those wires shortly. 3 or 4?
 
Found this on eBay....$780....But I am wondering if it is a genuine Pentair replacement.....because the Pentair logo is not posted on the pic.
I don't like the 'for pentair' start of it. A replacement cell is *a pentair* and not *for pentair* IMO. But language barriers, so. Lol

There was a couple of this type questionable ad in the $600s on ebay if you are a risk taker. If you dont spend the money on a 'EC' model they only give you a 60 day warranty anyway for online sales. Some brick and mortar stores online count as 'in person' but ebay sure wouldn't.
 

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Found this on eBay....$780....But I am wondering if it is a genuine Pentair replacement.....because the Pentair logo is not posted on the pic.
Weasel-worded.


I'll be looking at those wires shortly. 3 or 4?
If they have to tell you about how they’re on your side, it’s probably a sure sign that they aren’t genuine.
IMG_5522.jpeg
 
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the "For Pentair" is definitely what caught my attention too. I will only buy genuine Pentair.

OK, I hate to ask: After checking 4-5 websites for the "EC" version, what does the "EC" mean? The closest reference was "Extra Comfort" which I find to be a useless moniker. Is it an improvement I want?
 
E-commerce. Prices to this day are volatile and its possible to find an EC model cheaper, but it's usually a couple hundred more for the 1 year warranty.
 
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I would check with Marina. To my knowledge when you buy from them (over the phone) it is considered an 'in store' purchase and you receive a full 2 year warranty.
 
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Marina sounds good. I think a 2-year warranty on something like this is a good idea. In fact, the one I received from Pentair Store direct in 2016 had to be replaced under warranty too. I have a new flow sensor coming, should be here by end of the week, will first try the repair.....as my cell usage lights say 60% I might still have some time left on the original unit.
 
UPDATE: This thing is driving me crazy: While I wait for the new IC-40, the old one is now functioning differently (like working?). Yesterday it had only the RED light COLD water ON, all others out, which I had never seen before...Today it's normal operation as far as the Green lights except LOW SALT RED... So, I measured the salt and it's 3200 ppm. Water temp is +63 (looks like we are going to have lows around +35F next two days), so CL demand is low. I measured the FC (3.5 ppm) and will run the IC-40 on BOOST for the next 8 hours to see if any CL is being produced. It's very cloudy so little CL will dissipate from he sun, and my CC is near 0 also. pH around 7.6-7.8, TA=70, and CH around 325. CYA around 30 (I plan on running a SLAM this weekend before bringing that number up).
 

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