All heaters are built to almost the same specifications.
Unfortunately with all the chemicals added to the water and other pollutants these heaters are not lasting as long as they used to Especially the ones being imported.
I had several major problems with AO Smith including a brand new tank LEAKING near the top So much for testing and quality control huh?
Try American (Formerly mor flow or Branford white STILL a great company before they get bought out) Good luck
SylvanLMP