I have a 50w Top Fin submersible heater and I think it may be broken. The light blinks when it is on(not necessarily blink, in the sense of it turns completely off, it kind of looks like the light is moving back and forth) and makes odd sounds. Every once and a while I'll hear a hiss, or sizzle. I hope it isn't water leaking in. It heats the tank fine, the temperature of the water stays right, but I just don't know about this thing. I have 2 others, I have a 100w in my 20 gallon and it works perfectly, never had a problem with it, and I had another 50w in my friend's cichlid tank and it was doing the same thing. I took that one back to Petsmart and got my money back, but idk about this other one in my betta's tank. The 50w is only a week old, and I've had the 100w for about a month now, I got rid of the other 50w a few days ago. Any help would be much appreciated!