How many watts are your elements? Are they 240 volts?
Check thermostats for round red buttons.. these are manual reset high temp limit controls that pop at around 170 deg or so.
Just for your info,, as most water heaters I've seen, only one element is active at any time.. the top thermostat is a 3 way switch.. when its satisfied, it turns off and send power to the lower thermostat. When the lower thermostat is satisfied, it turns off too but still has power available. Since thermal currents rise, as the heater cools off, the bottom becomes cold first.
Hope that helps,