[LazyPup]

About a year ago Consumer Reports magazine published the results of an extensive survey and they said the across the board average was 12yrs.

On the other hand, the longest lasting water heater that I am personally familiar with was a Rheem AUI-40 gas fired glass lined 40gal tank in my mothers house. Last year we elected to replace it because the draft hood was almost completely rusted away although there still was no sign of a leak and it was producing plenty of hot water. While removing that tank I found the note that my dad had written on it saying that Dad and I had installed it in 1964.