I have a 10 year old 'Giant' brand 40 gal electric water heater. There is no sign of a sacrificial anode. A couple of days ago, we noticed a bit of brown in our hot water, so I drained it. I got quite a bit of brown gunk out of it. The water is still a bit brown, but is getting better. My wife mentioned this to a friend of hers who said that a similar problem had happened to her and that it was a crack in the glass liner. Eventually, the water ate through the outer shell and flooded her basement. Obviously, a poor outcome that we are trying to avoid. What are the odds that it is a cracked liner? How much time are we looking at (hours, days, weeks) before catastrophe strikes? Any input welcomed. Regards, Jim Tracy Nova Scotia