We live in Mobile Home with a Rheem water heater. We also have a well tank on the property. We recently lost power for the first time. (It was out for two hours from 6 a.m.) My husband went to take his shower within minutes of losing power. It takes several minutes for the hot water to reach the far end of the home and the shower, which is typical. When the hot water came; he barely got going and the water quit completely. Why wouldn't he continue to have hot water from the tank? It has to a 40 gallon tank?

Do you have a good strong flow of cold water at all taps? How many psi in the tank?

You say you have a well tank, which means you are on a well, therefore you have a pump which requires power to work. The water heater is only a holding tank, the well tank is a pressure tank. With power out, the tank will only supply maybe a minute or two of pressure before you run out of water. So basically, when the power is out, you will have no water. Once the power came back on, Im guessing water was fine again?