IntelliChlor Flow and Temperature Sensor FAILED

JoyfulNoise

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May 23, 2015
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Tucson, AZ
There are many threads on this topic but I just wanted to report that the Flow/Temp sensor in my IC40 that I purchased roughly about a year ago failed (not exactly sure when I installed it) ...:cautious: It was the Pentair OEM replacement (the $99 model on Amazon) so that was a costly $100 for less than a year's worth of service. The IC40 was installed in 2013 and ran until 2018 before the original sensor failure. The replacement got me one more year. The flow switch works fine, the thermistor is what went bad (all flashing % LEDs when in diagnostic mode). It's amazing how bad these sensors are. I think it may have failed sometime over the summer but, because the water temp was high enough, it really didn't affect the salinity much. I know my actual salt level is 2900ppm but the ET panel is reporting 2550ppm which is "VERY LOW SALT" but the water temp is 73F so it should be really close to the actual value since 10k thermistors are 10kOhms at 75F.

I have the in-pipe Pentair 10k thermistor used for water/air temperature measuring. I'll have to ponder my options of either installing the in-pipe thermistor and hacking the IC40 OR purchasing a generic flow switch for $50....laziness is the ultimate factor in deciding what to do ....
 
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Jimrahbe

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Jul 7, 2014
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Bedford, TX
Matt,

It takes about 15 minutes to drill a hole in a pipe and add the external thermistor to the IC40's wiring..

I just did one yesterday.. So far the one at my house has been working just fine. The thermistor in one of my rent houses went bad and rather than replace the flow switch, I just added the external resistor.

I had previously just cut the thermistor wire and let the IC40 run on the default valve.. I think about 75 degrees.. That fixed the initial problem, but I was a little worried about how that would work over the winter, so I went ahead and installed the external one..

When I bought the 10K probe, I also bought a small box of the Scotchlok connectors..

I make sure to leave enough cable so that I can still clean the cell in place if necessary.

Thanks,

Jim R.
 
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JoyfulNoise

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May 23, 2015
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Tucson, AZ
Matt,

It takes about 15 minutes to drill a hole in a pipe and add the external thermistor to the IC40's wiring..

I just did one yesterday.. So far the one at my house has been working just fine. The thermistor in one of my rent houses went bad and rather than replace the flow switch, I just added the external resistor.

I had previously just cut the thermistor wire and let the IC40 run on the default valve.. I think about 75 degrees.. That fixed the initial problem, but I was a little worried about how that would work over the winter, so I went ahead and installed the external one..

When I bought the 10K probe, I also bought a small box of the Scotchlok connectors..

I make sure to leave enough cable so that I can still clean the cell in place if necessary.

Thanks,

Jim R.
Which size (color) ScotchLok connectors did you get? If I recall correctly, the wires are 22 gauge...
 

JamesW

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Mar 2, 2011
16,599

Almost exactly 1 year since replacement.
 

Jimrahbe

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Bedford, TX
Matt,

The box says .. "UR2" says it is for 26-19 AWG... It has places for three wires, but obviously you can just use two of the holes.

It is also much better to have the right size band clamp before your drill the hole in the pipe.. :mrgreen:

Jim R.
 
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JoyfulNoise

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May 23, 2015
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Tucson, AZ

Almost exactly 1 year since replacement.
I actually checked my PoolMath App and I had put a note in there on Oct. 14th 2018 that I changed the sensor. Having thought about it more, I noticed over the summer that my salinity was reading close to my K-1766 results in the early months (Jun/Jul) and then I recalled looking at the salinity later on and it was suddenly up around 3800ppm (almost 1000ppm higher than K-1766). I didn't really care much at the time but I wish I had made a note as that was likely when it failed. So I do believe it was operational for less than a year. Really sad how poorly made these parts are.

I think Jim has convinced me that the in-pipe thermistor is the better deal. I have to tear down my filter anyway and check the thermal regulator on my Mastertemp 400 so I've got lots of PM work to keep me busy one of these weekends....
 
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JamesW

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Mar 2, 2011
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I think that Pentair is using a new flow switch. I don't know if it's more reliable, but I suspect that that's why they replaced it.

 

JoyfulNoise

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May 23, 2015
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Tucson, AZ
I think that Pentair is using a new flow switch. I don't know if it's more reliable, but I suspect that that's why they replaced it.

It still looks like a Harwil sensor and there's no way to know on Amazon if you're getting a new one or an old one as the part number isn't any different...
 
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JoyfulNoise

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May 23, 2015
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Tucson, AZ
Matt,

The box says .. "UR2" says it is for 26-19 AWG... It has places for three wires, but obviously you can just use two of the holes.

It is also much better to have the right size band clamp before your drill the hole in the pipe.. :mrgreen:

Jim R.
Thank Jim!

I ordered a box on Amazon. When I get a free weekend it looks like I'll be spending a lot of daylight hours out by the equipment pad cleaning the filter and PM'ing stuff.

What size band clamp did you get? I've got some in the garage but I don't think they're large enough. Also, what size drill bit did you use to make the hole? I have my pipe clamp drill guide that lets me drill a straight hole so I'll finally get an opportunity to use it...
 

Jimrahbe

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Bedford, TX
Matt,

I have a drill driver kit that I put a handful of drills in... I just fumbled around until I found one that was big enough.. I went out to my workshop and fumbled around some more and it looks to be a 13/32nd.. I just free-hand drilled the hole.

Same thing goes for the band clamp.. I have a bag full of different sizes and just fumbled around until I found one that was big enough.. Sorry, I have no idea the specific size. Obviously bigger than 2".....

If I had used a pipe clamp drill guide, I'd still be there reading the instructions.. :mrgreen:

Thanks,

Jim R.
 

JoyfulNoise

TFP Expert
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May 23, 2015
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Tucson, AZ
I fixed my cell with a used rectal thermometer from a local urgent care... money is tight in the Davis household.

Maybe grease up the old flow switch with some CBD palm oil?
We could grease you up with some CBD oil and then maybe your amateur pole-dancing gig at the local Masonic Lodge will start to take off....
 

bdavis466

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Aug 4, 2014
5,066
San Clemente, CA
We could grease you up with some CBD oil and then maybe your amateur pole-dancing gig at the local Masonic Lodge will start to take off....
I think the locals have really grown to like my unique style and they sure do get silly when I do my signature triple reverse double jackhammer thunder clap⚡

Maybe I can incorporate a thermistor into my routine... the hotter it gets, the more salt water I produce!
 
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needsajet

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Jan 4, 2016
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Sydney, NSW, Australia
Not suggesting what to do, but perhaps just for interest... I put the thermistor on the outside of the pipe so it stays dry. I added 3/4" (20 mm) thick foam pipe insulation over it, surrounding about 6" (150mm) of pipe. (3" (75mm) either side of the thermistor)

I did some tests before I tried that approach, and it delays the reading by about 15 seconds as the PVC pipe changes temperature, and is about 0.25 degrees C different from the water temperature (around 0.5 degrees F) when there's a large difference between pool water and air temp.
 

JoyfulNoise

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May 23, 2015
15,895
Tucson, AZ
Not suggesting what to do, but perhaps just for interest... I put the thermistor on the outside of the pipe so it stays dry. I added 3/4" (20 mm) thick foam pipe insulation over it, surrounding about 6" (150mm) of pipe. (3" (75mm) either side of the thermistor)

I did some tests before I tried that approach, and it delays the reading by about 15 seconds as the PVC pipe changes temperature, and is about 0.25 degrees C different from the water temperature (around 0.5 degrees F) when there's a large difference between pool water and air temp.
Interesting....but I'm still going to drill into the pipe :p

My equipment pad is in direct, HOT sun all through the late morning and until sun down. The air sensor sits under the ET panel and hangs there with no direct sun but routinely registers 120-130F during the hot summer days. It's definitely picking up the heat coming off the side of the casita so I've always just ignored it really since I don't have a solar heating setup. If I were to install solar I'd need to find a more suitable location for the sensor to more accurately sense air temperature. So I guess what I'm saying is that putting the thermistor on external to the water flow could introduce too much error in my case.

But it's a nice idea nonetheless....
 

proavia

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Feb 6, 2015
1,628
Chandler AZ
I don’t want to beat a dead and over heated horse, but how bouts you pull in the reins on the “production” you got goin on over der, and build yourself a shade structure for your equipment pad?!? Just sayin.....
View attachment 122009
I bet that equipment shade structure is already penciled in on his schedule - right after he purchases and installs Screen Logic for his pool automation system. But he may have to change the timing as prime "oil" pressing season is upon him.