Hayward T-CELL 15 on death row

[Red]

I first went to SWG in 2010. I have an AquaRite PRO system from Gold Line/Hayward. The ORP thing never worked well, so I went to a percentage setting instead. (The pH works really well and I'm happy with that.)

Here's the rough timeline of my AquaRite PRO experience:

Date	AquaRite Pro Logic Board	T-CELL 15
Feb 2010	New	New
Aug 2014	Stopped working; Hayward authorized repair checked it out and replaced it (it was out of warranty and expensive)
Feb 2015		Replaced with new Hayward T-CELL 15
Aug 2016		T-CELL not working. Authorized Hayward dealer determines it's defective and replaces it with a warranty replacement T-CELL 15
Apr 2019		Negative polarity appears be having problems; positive appears to be working

Overall, I've received at least 3 years since my last T-CELL purchase, so I guess Hayward has fulfilled its warranted use; however, I'm wondering if the warranty replacement T-CELLs are somehow not designed to last as long (it is clearly labeled as a warranty replacement)? If it's not different than the real thing, I'm still concerned that it didn't last at least 3 years and wonder if I have some other problem?

Since my current cell seems to be working when it's on positive polarity, is there any harm in continuing to use it until it fully dies? I figure I can just increase the percentage use, if necessary, to get the amount of chlorine I need. I cleaned the cell with an acid solution last week and it's still behaving the same. The controller alternates between + and -. When it's on -, the volts and amps are low and the salt sensor is way off and the low salt warning turns on. When it switches back to +, it thinks everything is fine.

 

[ajw22]

Post the diagnostic tests.

What level do you have your salt? Do you check it with a K-1766 Salt test?

@Jimrahbe @JamesW thoughts?

 

[Red]

Here are test results:
From AquaRite PRO

Item	+	-
Volts	26.09	28.00
Amps	6.10	2.79
Salt	2800	0800

I misstated above that the volts were lower on -; it's just the amps.

Here's the chemistry

Test	Result	Comment
FC	7.5	I know it's a little high for TFP recommendations. I usually run it a bit higher than TFP and it's also higher because I added some liquid chlorine before being out of town a few days, as I wouldn't be around to check levels.
CC	0.5
pH	7.5
TA	70	It dropped this week. I'll be adding a bit of baking soda.
Temp	74 F
CYA	60
Salt	3400	(K-1766 test) Note that it's higher than what the + side of AquaRite indicates (2800). My experience is that the AquaRite sensor is always lower than an actual measurement. Looking at my history, the 2800 AquaRite/3400 Taylor result is a relatively normal difference.
CSI	-0.35	Potentially corrosive. I'm adding some baking soda to balance it.

 

[ajw22]

FC of 7.5 is fine. So is TA of 70. Don’t add baking soda to raise it.

Nothing corrosive about CSI of -0.31. Guidelines are keep CSI between +0.6 & -0.6.

Your CSI will rise as your water warms in the next few weeks.

That is better on your cell. I was worried you had a power supply problem. The amps are low on the - cycle because the salt sensing is broken. The cell is failing but if you can get the chlorine you need from it then keep on running it until it dies.

 

[Red]

Thanks for your thoughts on this. It's the TFP calculator that calls it "potentially corrosive," so I've tried to make changes to get it back to balanced when I head into the potentially corrosive zone. I ran out of time to add some baking soda yesterday, so I'll just wait and see how things look next week.

 

[ajw22]

Any corrosive effects from a CSI at your level takes months and years, not days or weeks to happen.

Let your pH drift up towards 7.8 and your CSI will rise. Your CSI will also rise as your water temperature increases.

I would not raise your TA.