So I have an aquatop 75 watt heater in my 20 gal tank. I did a water change and forgot to unplug the heater. I smelt something burning and realized my heater was still running. It was out of the water for probably 3-4 minutes. It's a glass heater and around the glass looked like a burnt substance, but easily came off with water, though it kind of melted the plastic clip that was holding it to the tank. Anyways I unplugged it, cooled it off, inspected it, no cracks or leaks, put it back in and let it sit for 30-40 minutes in the water before turning it back on. It's been a few days and it seems like it's working. It shuts itself off when at the desired temp. Do you think it's still safe to use? Or should I get a new one?