My parents are having trouble with their Bradford White water htr. At first the bottom element went out. They had it fixed then a couple of weeks later the other element went out and was replaced then a week later no hot water again so the top and bottom thermostats were replaced and they only had warm water for a while and now just cold water. Both elements and thermostats have been replaced and the tank does not leak. Does anyone have any suggestions? Thank You very much!