My RIO 2500 also melted in the sump last year. It was only 14 months old. The whole house smelt like burnt electrical when I got home and the breaker had blown. Lucky for me the RIO pump was in the sump and when the power tripped, and no contaminated water entered the display tank. I would NEVER buy a RIO pump again. If you have a RIO in your display tank, consider removing it.