7 Year Old A.O. Smith Water Heater - Tank Rotting
I have a 7 year old A.O. Smith GPSH 50 200 water heater. It was considered to be a pretty decent unit when my builder installed it in my new home in 2005, and for the most part I haven't had any complaints about it. The other day when I was in the basement, I noticed that there was a puddle forming between it and the condensate pump for my AC. I figured that my condensate over flowed, so I wiped it up and watched, and soon I noticed that the water was coming from my water heater. I pulled the panel off on the bottom, started looking around with my flashlight, and soon discovered that the water was coming from a pretty badly corroded area where the drain valve screws into the tank. I checked to see if maybe the valve was bad, but it was pretty clear that the moisture was coming from the area at the tank where the nipple flares out for the valve to screw into (not from the threaded area).
I'm now resigned to the fact that I'm going to need to invest in a replacement, but a few things have me curious.
First, since A.O. smith seems to be a fairly well respected brand, is it common for a tank to rot out after only 7 years? I never did replace the anode on it, but I didn't really think it would need it yet. Keep in mind, it is fairly well treated municipal water in Pennsylvania.
Secondly, where is the anode on this unit? I only see one "pop out" cap on the lid, and it is packed with solid foam under it. Do I need to cut the foam out, or is there another place I should be looking on this unit.
Finally, I live in a 3 person household, what would be a good unit to replace this one with?