I'm glad this thread has come up. I'm at the stage now where I don't have any confidence with any heaters. So I got inkbird units for my tanks and they failed too! I mean, how difficult can it be for these companies to manufacture reliable heating systems?
At the minute i'm running juwel aqua heat 300's (on their own, no temp controllers due to my ongoing inkbird issues). I've had one issue so far and that was when one of them stuck on and my water hit 90 degrees overnight which is a shocking issue to have with any heater.
Everytime I walk past my tanks now i'm checking the thermometer, i'm touching the glass, i'm dangling my fingers in the water. I'm the best temperature controller for my tanks at the moment so i'm hoping that this thread can identify a brand of heater that is reliable and i'll give them a try. I don't even mind paying silly money for a heater, after all it's probably the most important piece of equipment in a tropical set up.