[mike31154]

Trouble with a controller is, sure it will prevent a stuck heater from cooking your tank, but it won't stop a heater from bursting or exploding. Nor will it keep your tank from getting too cold if a heater doesn't work. It's another level of protection for sure, but also another point of failure itself. No absolute guarantees no matter what you do. You can decrease the odds of something ruining your day by adding levels of protection, but there's a point where redundancy also becomes complexity. Daily personal monitoring is the only way to really be sure. If you're away a lot, your odds increase of something going wrong no matter how many backups you have. Even an email from your controller that something's up while you're on the beach in Mexico enjoying a Cerveza is not going to do that much to prevent at least some chaos until you either return or have someone fix it pronto.

Kien makes the point by saying he has no idea a heater is working or not unless he unplugs it from his controller & hooks it up independently to see whether or not it's working as it should. One of the reasons I went back to at least one glass heater is because I can see the pilot light turn on/off as the heater thermostat is doing its thing.