Intellichlor IC 40 Corroded (melted) spring steel on flow switch

[FaustFamilyPool]

I am having an ongoing issue with the spring steel on the flow switch failing. I’m looking for some advice on what the issue could be.
Here’s what’s happened thus far:
- IC40 was installed
- After about 4 weeks the sensor failed.
- I ordered a new one on Amazon. Pentair factory replacement.
- I installed and sensor was good for the two or so weeks it was in.
- Minella Pools ( local pool company I purchased cell from) Replaced the cell under warranty and left the switch I had purchased for me in case I needed later.
- The sensor on the whole new cell failed after about 5 days. (3 days ago)
- I reinstalled the extra replacement sensor and it failed again today. It failed in 2-3 days this time.

Each time, the spring steel of the flow sensor appears to be melted away. As in very quickly corroded.
1. Do you think this could be an issue with the controller?
2. Is it a water chemistry issue? I do not think it is. I fully check weekly. Never a major high chlorine issue or major PH fluctuation.
3. I have my tab chlorinator outlet about 18”-24” down stream (after) in return piping. It is in the “off” position. The water in it seems extremely chlorinated.
Could it possibly be back feeding that corrosive water through during the “pump” off cycles and melting that spring steel?

The replacement sensor went 2 weeks and when I re-installed two days ago after the second failure it looked perfect. It melted out two days later....

The only thing I can think that is different is that I believe I had the tab chlorinator empty when I had the two week run with no trouble.
~ Mike.
pool chem

6/2/21 7pm
Notes: Salt cell repaired 3 days ago. Flushed to lower level 3 days ago. Chlorinator turned off. Set for 20%. Pump schedule 7-12p and 3-8p. 2800 rpm. Pressure 12psi.
Pump pressure 14psi
Pump cycle info
Chlorine 4pp
Combined .5ppm?. pm
Total chlorine 3.5ppm
Salt - did not test. Cell range good
CYA - goal 60-80. 70ppm
CH - goal 250-400 today 250ppm
TA goal 60-90. 66TA
PH goal 7.2. Today 7.5
Temp 70

 

[mknauss]

Welcome to the forum!
I can honestly say I have never seen that shown here on the forum.
Why are you using trichlor if you have a SWCG? Do you have a check valve between the trichlor thing and SWCG?
Let's see if @JamesW has some guidance for you.
I suggest you read ABC's of Pool Water Chemistry.

 

[FaustFamilyPool]

High. I’m having an issue with my IC40. it keeps eating up the flow sensor spring steel. I posted my water chemistry below. I cannot figure out what is going on.

Here are some of the details.

I am having an ongoing issue with the spring steel on the flow switch failing. I’m looking for some advice on what the issue could be.
Here’s what’s happened thus far:
- IC40 was installed
- After about 4 weeks the sensor failed.
- I ordered a new one on Amazon. Pentair factory replacement.
- I installed and sensor was good for the two or so weeks it was in.
- Minella Pools ( local pool company I purchased cell from) Replaced the cell under warranty and left the switch I had purchased for me in case I needed later.
- The sensor on the whole new cell failed after about 5 days. (3 days ago)
- I reinstalled the extra replacement sensor and it failed again today. It failed in 2-3 days this time.

Each time, the spring steel of the flow sensor appears to be melted away. As in very quickly corroded.
1. Do you think this could be an issue with the controller?
2. Is it a water chemistry issue? I do not think it is. I fully check weekly. Never a major high chlorine issue or major PH fluctuation.
3. I have my tab chlorinator outlet about 18”-24” down stream (after) in return piping. It is in the “off” position. The water in it seems extremely chlorinated.
Could it possibly be back feeding that corrosive water through during the “pump” off cycles and melting that spring steel?

The replacement sensor went 2 weeks and when I re-installed two days ago after the second failure it looked perfect. It melted out two days later....

The only thing I can think that is different is that I believe I had the tab chlorinator empty when I had the two week run with no trouble.
~ Mike.
pool chem

6/2/21 7pm
Notes: Salt cell repaired 3 days ago. Flushed to lower level 3 days ago. Chlorinator turned off. Set for 20%. Pump schedule 7-12p and 3-8p. 2800 rpm. Pressure 12psi.
Pump pressure 14psi
Pump cycle info
Chlorine 4pp
Combined .5ppm?. pm
Total chlorine 3.5ppm
Salt - did not test. Cell range good
CYA - goal 60-80. 70ppm
CH - goal 250-400 today 250ppm
TA goal 60-90. 66TA
PH goal 7.2. Today 7.5
Temp 70

 

[JamesW]

what the issue could be.

It's probably the tab feeder.

Get rid of the feeder.

Could it possibly be back feeding that corrosive water through during the “pump” off cycles and melting that spring steel?

 

[FaustFamilyPool]

Welcome to the forum!
I can honestly say I have never seen that shown here on the forum.
Why are you using trichlor if you have a SWCG? Do you have a check valve between the trichlor thing and SWCG?
Let's see if @JamesW has some guidance for you.
I suggest you read ABC's of Pool Water Chemistry.

Thanks for the welcome! I’ve been following the TFP site for two years now, but haven’t had a need to post.
Yes this is a tricky one. I think the Hayward auto chlorinator is somehow releasing highly chlorinated water into the vicinity of the flow switch during shut down. My next step is to completely empty and flush the container upon installation of the new sensor. As I believe the longest run was when the canister was empty.
I don’t know why I left the auto chlorinator installed. Just seemed like a good idea to leave it there just in case.
No, the recommended check valve is not installed. I will be doing that before the next sensor goes in as well.

Special Note: I do have a weekly service from a pool company. That relationship is going end this week. I just can’t seem to keep ,y hands out fo what they’re doing. I have the water chemistry all figured out far as timing for adding chemicals and etc. they just seem to come by and randomly dump Crud in the pool and mess me up.…

 

[mknauss]

If you remove the trichlor thing, you do not need a check valve.

I suspect if the water acidic enough to destroy the flow switch, the SWCG cell plates will not last as long as they should. The rare earth minerals they are coated with are susceptible to damage with very low pH.