Sorry to hear about the heater. Did that heater have a temperature probe? I have a couple of those that were given to me because they weren't working. I fixed them by replacing the fusible link/thermal fuse, a protective device to keep them from over heating.
It's possible that it had the wrong one(Higher wattage) or the parts continued to touch after it melted through. I burned out one once because I started a water change and left for an hour. The heater blew the fuse because the temperature probe was only a couple inches from the rim of the tank and being exposed to the cooler outside air temperature after I drained the water.
I use two heaters of the same wattage in my big tanks, they don't have to work as hard and you'll still have heat if one stops working.
If you are planning on tossing that heater out, you can toss it to me