Sold and installed an electric water heater a couple of months ago, the customer did the startup as he didn't have water or electrical turned on yet. Got a call, either VERY hot water, or no hot water and ECO (red reset button) is tripped. I checked power, thermostat settings (both were set to 125). No power fed to upper element, the bottom element had power and was heating. I drew some water from the T&P valve, it was only reading 110. I played with the upper thermostat setting. To get it to send power to the element, I had to set it to 140. So I knew it was bad, changed it, and the upper element energized and started heating. But the extremely hot water and the tripped ECO was bugging me, couldn't figure out why those had been occurring. After thinking it through, here is what I think was happening. The upper thermostat was obviously reading incorrectly, so it was never sending power to the upper element, so the water toward the top of the heater was not getting hot before the bottom element turned on. The bottom element stayed energized, and was continuously heating water, but the bottom thermostat was never cutting power to it because the hot water was displacing to the top of the tank. The water at the top of the heater was getting very hot, up until the point that it was tripping the ECO. Whatchya think of my conclusion?