How to repair your Hayward T-CELL-X vs buy a new one. Incomplete - my findings and has anyone figured this out?

[caliskier]

Hi all,

Preamble:
I came to this site years ago because I do everything myself. When something expensive breaks I try to figure out how to fix it, vs get a new one. I have measured and replaced my in ground pool liner, changed my timing belt on my odyssey, and replaced my own iPhone glass. All that to say, i can do it, and for me, if I can do things nobody else is doing, I get to have the money to do things nobody else gets to do. That's a little more than you needed.

Why I am posting this:
I know my T-CELL-15 is getting on in age and, while it is producing fine, I am expecting its inevitable failure. If that happens today, its $900 + tax. I think it can be fixed

Here is what I have found:
Ebay has sellers that will take your broken T-CELL-X and fix it for you - If they can do it, I can do it.
Guy on youtube took apart his T-CELL-5 - He points out that it appears Hayward installed the Thermistor in a way that its not possible to replace it, forced obsolesce. There are manufactures out there that will pour epoxy all over the circuit board so you can't possibly repair it.

That is interesting on its own, but... If you read in the comments under that youtube link someone said this:
The most common component to fail on these units is the Thermistor that is inside the Cell that is shown in the video. The Thermistor is used to determine the water temp and salt level. If the Thermistor fails, you will more then likely get a "HOT" error on your panel. If you check the Molex connector, pins 6 and 10 connect to the blue and red wires. You can use a multimeter to check the resistance and continuity. The resistance should be around 10K ohm, +- 2K ohm depending on your temp. If you see reading that are way too high or low then your Thermistor is cooked. The easiest fix is to slice the power cord cable sheathing and expose the wires. The blue and red are the ones you need to work on. Cut the wires and solder a 10K ohm resistor between the red and blue wire that are facing the Molex connector. Give the unit a test and the error should be gone. Tape everything backup up with some electrical tape and you are done. The 10K ohm resistor has the control panel think that the water temp is 77F. Fixed my unit this way and it works perfectly. One dollar resistor and 2mins of soldering saved me $1000 for a new unit...

Ok so what's the point, what's the question?:
Questions are:

1. Is it true that the Thermistor fails on these more often than anything?
2. This solution bypasses the Thermistor, fooling the unit into thinking its 77 degrees, but the Thermistor also tests the salt ppm, right? If you use a test kit, what is the downside?
3. Are there any other good solutions for fixing these units vs dropping almost $1000 on a new one?
4. What other thoughts does anyone have on this?

I am very curious, and I can see myself in the future coming right back to this to move forward when it eventually does fail.

Thanks all

 

[markayash]

Don’t know anything about the cell but like your thinking.
Years ago my furnace was acting up and they wanted a fortune for a new circuit board. I took it out and fixed a cold solder joint and the owner said “ you know how to solder?”

Let me know how it goes

 

[mknauss]

WARNING -- The modification of a Salt Water Chlorine Generator can create or disable safety systems inherently designed into the system. Such as above, using a resistor to bypass a thermistor will create a condition that the SWCG will NOT recognize low water temperatures. If the SWCG is used at water temperatures below 55F, it is likely the SWCG cell plates will be damaged.

Thank you.

 

[caliskier]

WARNING -- The modification of a Salt Water Chlorine Generator can create or disable safety systems inherently designed into the system. Such as above, using a resistor to bypass a thermistor will create a condition that the SWCG will NOT recognize low water temperatures. If the SWCG is used at water temperatures below 55F, it is likely the SWCG cell plates will be damaged.

Thank you.

Thank you! That is a good thing to remember. The thermistor cannot be replaced so the cell is technically dead. If I bypass the thermistor I just need to make sure I am not running it below 60 degrees and make sure the salt level is between 2700 and 3400 ppm.

 

[caliskier]

Ok posting for myself in the future and for anyone that wants to know. I predicted in April my unit would fail and it is now failing. What that looks like is tested salt and low machine salt values. Big thanks to MKNAUSS, a lot of help from him...

The guy on youtube got me started in the right direction to try to fix it, but I know now that my problem is the plates, and mknauss helped show me that: T-15 SWG says 3000, test kit says 4600?

One thing you can do while the cell is failing, you can change the system to think its a T-9 and that might get you more life, that is what I am doing now and the salt value in the system is reading 500-600 ppm higher.

Some helpful links below here to help other figure out how to fix the thermistor. T-15 Cell "Hot" Error, Salt Reading Low - SOLVED (dead thermistor)

Mknauss provided a very helpful link, many details about how the salt cell and unit work: Hayward Aquarite SWG - Further Reading

Ok the thermistor replacement will not work for me, but I really appreciated the community on this one. I measured my resistance and my thermistor is fine: 10.42 kohms. My Salt is 4200ppm which i know is way too high because I trusted the machine and not my tester. So finally I figured out how to read the year on the serial number, and mine is 8 years old. These are supposd to last around 7 years, that may be your problem, I think it is mine.

To figure out how old it is, go here: Hayward Serial Numbers and Date Codes - Further Reading

Thanks all...