I've had an energy bar fail. Sort of an odd case but here is the short story and summary of it. I'd like to second what
@robbyg said above about the best defense being redundant systems for critical devices. With that being said I know have a backup / standby unit after my failures.
In a nutshell car accident took out a power line, then started a fire, then in the process the utility company had an issue which sent in 3 times the normal power into our neighborhood. A surge I guess. Power goes out, I hear loud pops in the garage, check it out, see a few more plus electrical arcs visible from the solar power inverter. Darn thing almost started a fire. Anyway related to the energy bar failure once power was restored the energy bar didn't come back online. Tank was fine more or less because I have a Cor 20 return pump a different outlet for this reason. I took that time to assess the house, fix what I could, note what I couldn't, and then the next day get back to the bar.
Ended up that I needed to reset the breaker on the energy bar or the thing that is tripped when this sort of thing happens. I guess like a normal surge protector. After I did that power and stuff worked but the 1link module wasn't working or responding. So 2 cor 15 return pumps and the Trident - 1 link connectivity. I tried a few more times, reset it again, and power finally came back. Few months later after cleaning one of the Cor 15 return pumps it failed again. Created a ticket with support and they asked me to try a few things.
In the end and reading some conversations about automated testing here and controllers,
@robbyg above took part who has a pretty extensive background, I said to myself I'll just buy a new one, swap it in, and if it fixes the problem RMA it to neptune to fix. They did and 50 bucks later I now have a spare.
So yeah, I had a failure but I believe it may have been caused by something unrelated to the product and a side affect a power surge into my home. We lost the solar inverter, dishwasher, 2 refrigerators, thermostat, etc. Crazy, huh? But with regards to backups, spares, I'm a believer now.