That mechanical flow switch on your Aqua-Rite is the weakest point of your system. Mine lasted exactly one year and a day (so-long guarantee period!), and then failed closed, leaving my cell in operation overnight after my VS pump shut down on its internal timer. At that time, I was still a pool noob, and detected the problem after only a day or so because I couldn't leave anything alone. Although I had no catastrophic failure, the internal plastic vanes in my cell must have got pretty warm, because they aren't straight any more.
My bent-vane cell still produces chlorine over a year later, but I could have lost a $400 cell or worse because the cheap mechanical switch crapped out. The Aqua-Rite installation instructions clearly state that the system MUST be on a timer, as the switch is considered an auxiliary safety device, not a primary shutoff.
I should have stomped into my pool contractor's office and demanded that they fix the problem, but it was their electrical subcontractor that did it, and I had already stomped in there multiple times for other problems.
After a bit of reading on this site, I added a current-sensing relay that I bought from Amazon to the supply leads to the Aqua-Rite. If my pump isn't drawing sufficient amps. my Aqua-Rite won't come on. The relay fit in the box, and the city permit gestapo isn't even aware of it. It's a solution that enables the VS speed pump to retain power for its brain/timers overnight and doesn't require another box on the side of my wall, electrical permits and a couple hours of electrician time.
Other people here have done the same thing - do a search for more information.
Here's my post from 2016, when I did it.
