I just bought a new Visi-Therm 300w heater two weeks ago. It literally exploded about two inches below the on light, that shows it is heating. It pays to have a grounding rod in the sump. Can someone maybe explain why this would happen? It was completely submurged all but the top inch or so. All I can think of was the bubble diffuser on my protein skimmer was right above it and air bubbles where getting down on the heater. Might this have caused this? I now have heart trouble....LOL Scared the S**T out of me and my wife!!!, Blew the breaker I was running around the house like a chicken with my head cut off, and all my wife could do is cuss me saying " I am missing my show on TV for you overloading the electic." This has been running this way for two years and never have overloaded the electic. (My wife has her priorities in the wrong place.)LOL In the long run everthing is A-OK.
John
John