Not long ago I bought a house with a pool equipped with an Aqua Rite SWG system. This is completely uncharted territory to me, never having owned a SWG pool and my only previous pool experience was 45 years ago when I lived in Iran for a couple of years.
The previous owner of the new-to-me-pool had the balance all screwed up because unknown to him the SWG was not functioning and he was "shocking" the pool nearly every day, thinking that the system needed a "little help". He also was running the pump 24/7 and told me that continuous running is necessary to keep the pool operating properly.
After some research and some fiddling around, I replaced the surge capacitor on the control board and got the SWG working. I also started correcting the chemical balance, solving the black algae problem, reducing excessive CYA, etc. I finally got all that squared away.
I also reduced the run time to a few hours per day and that's when my problems started. Each time I checked the Aqua Rite panel, it showed a "low salt" and "check cell" warning. Resetting the system, by turning it off and on, solved the problem and it would function properly until the next time the pump cycled off.
The Aqua Rite trouble hot line clerk told me this is a symptom of a failed cell. I had my doubts since it produced plenty of chlorine once I reset the system each day and the voltage and amperage readings were completely normal. I gave the Aqua Rite tech all the displayed values, but the fact that they were all normal didn't seem to mean anything to him. He did not even try to explain how a seeming normal cell could produce plenty of chlorine and yet still need replacing. Nevertheless, I replaced the cell anyway because I foolishly believed the Aqua Rite phone talker, and I didn't know the history or age of the existing cell. It is hard to trouble shoot with zero previous experience coupled with bad advice from the factory. I asked for help on several pool forums, but got no help on the Internet either. The problem remained, so I replaced the control board. It was then that I noticed that the SWG continued to run when the pump timer switch shut off. This is, of course, completely wrong.
Apparently, what was happening was when the pump shot off, the cell kept working until it depleted the salt in the water trapped in the cell (it is mounted horizontally, "belly" down). Then the board detected low salt, turned on the warning, and shut down the cell. When the pump was running, I could reset the system and it worked OK. Thinking back, I realize that I had been either checking the system when the pump timer was already running or I was turning on the pump manually as the first step when I arrived at the control panel. It never occurred to me to check the cell function with the pump off.............I guess I just assumed it was wired correctly since it was at least several years old. Stupid me.
Connecting the SWG to the pump timer solved the problem. Unfortunately, I spent quite a bit of money on components that did not need replacing. The Aqua Rite people were of no help at all and actually led me down the wrong path, which cost me around five hundred bucks when it was all over.
It would seem to me that anyone with experience with a SWG system could instantly trouble shoot my problem given the symptoms.
So if your system is giving a "low salt" and "check cell" warning each time the pump shots off, yet functions normally when you reset it, it might be improperly wired like mine. Bottom line: The SWG should only have power when the pump is running.