re: water heater problem

I had the same issue, hot water running out quickly. I came here for advice and got it. Note-my tank is electric, so that's where we differ. I checked my heating elements first, and according to my voltmeter they were still in working order. Then I flushed the tank, and low and behold there was a shitload of sediment. After flushing it a few times, the tank is back to working properly.