My electric hot water tank is putting out very hot water. Can I find out which thermostat is bad without an amp meter? The top one clicks off at a high temp, and the lower at a lower temp.
So, did you try turning the thermostats down? And did the WH continue to heat? Usually the coils make some noise as they heat the water. Like a pot on stove.
Try dialing them up and down. If there is one that never shuts off then that one is broke.