Electric water heater stopped working when I adjusted the thermostat
Electric water heaters are easily repairable if you can get the old heating elements out of the tank.  If they get too corroded, you may not be able to remove them without damaging the tank.

But, that is a bit premature.  You need to test the resistance of the heating elements to determine if they are good.  You can also check that the thermostats are supplying voltage to the elements.  Note that this requires working around live, unshielded 240v connections, so you need to be careful and be sure it matches your comfort level. 

The thermostats and elements are pretty standard and you should be able to find replacements at a typical home store.