I have a "Clormatic" brand generator, and after 4 years it failed. The cell was warranted for 2 years, and prorated for an additional 3 years.
I'm convinced that ignorance on my part contributed to the failure.
I was unaware that elevated levels of "Nitrate" and "Phosphate" in the pool water significantly reduced the efficiency and hence the chlorine output of the cell.
I purchased NITRATE test strips from "Hach" company , catalog #27454-25, and "PHOS-Free" from the local pool store. This solved my problem after I dumped and refilled a third of the pool.
You need to be aware that with Nitrate and Phosphate in the water, the 26volts DC imposed on the cell is not producing the proper quantity of chlorine,and is reducing the life expecting of the cell.
Use fertilizer with caution around your pool.