Aks35 faulty. Is my cell dead? Are cells interchangeable?

[tomfrh]

I have an AkS 35 chlorinator and cell. About 5 years old.

Poolrite AKS 350 35g Pool Chlorinator 4Y Warranty (Retrofits All AKS, Surechlor, Enduro & Endurochlor Chlorinators)

Made by one of the largest and longest established pool equipment manufacturers, the AKS chlorinators is a robust, long lasting, efficient chlorinator that will perform with no issues

poolandspawarehouse.com.au

Recently it started showing lower Chlorine output, and pool chlorine levels have been dropping. It won’t go above 3 bars out of 8. The power control knob (potentiometer?) acts properly for the first half or so, and and brings output up to 3 bars, but makes no difference if you turn the dial further.

The salt levels are sufficient (~5000).

This unit is self cleaning. I’ve never had to clean the cell. There was nonetheless some minor build up on the cells, which I cleaned off with mild acid, but the low chlorine output problem persists.

The cell plates look clean. There is gas coming off the cells, the only problem is the power won’t go above 3 bars.

Any ideas?

Could it be the cell? The cell looks fine and bubbles on all plates.

I wonder if the unit is faulty somehow and is maxing out beyond a certain throttle point.

I’m considering trying a different unit, and leaving the cell intact. Are the cells generally interchangeable?

 

[YippeeSkippy]

Tom, I looked in the archives and can't find anyone else using that salt system. Perhaps it is only available down under?
Do the local pool stores there have a way to test the cell? It does sound like its failing since your FC levels are dropping.
Is that system worth trying a replacement cell (same brand) or should you start looking for a new Salt Chlorine Generator?
I'm sorry that's all *I* can think of?

Maddie

 

[tomfrh]

I can take the cell to the pool shop.

How do they test them?

Is there any way to see if a cell is failing? What are the symptoms of a cell going bad? Will something be corroded? What actually happens when a cell “wears out”? Is it literally something disintegrating?

The plates look good on this cell, and it’s definitely producing gas. But it is 5 years old.

 

[YippeeSkippy]

Did you ever clean the plates?
What is the size of the cell- we always recommend using a cell *at least* 2x the pool volume.
How many hours per day and at what percentage did you run the cell?

 

[tomfrh]

I only cleaned the plates last week, after it started playing up. The self cleaning feature has always kept it clean.

Pool is about 50,000L. I’ve always runs the chlorinator in the range of 5-50%. I run 12 hours a day on low flow pump. I adjust the chlorination throttle depending on the season, to maintain around 3-4ppm FC.

Even now, with the cell struggling at 3 bars, the pool is remaining acceptably chlorinated. It’s summer here and we use the pool a lot.

 

[YippeeSkippy]

Ok, I was worried you were going to say you cleaned it a lot routinely, which shortens the lifespan of the cell. So we can drop that issue.
I can only think the cell has failed.

 

[tomfrh]

I think you're right that it's the cell. I removed it and had a closer look. The internal faces of the plates have lost much of their coating. I will try a new cell.

 

[tomfrh]

It was the cell. I replaced it and it’s working properly again.