Here is some basic checking you can do. Take off the case and remove the top 1/2 of the controller board carefully. On the top there will be 2 brown wires for heater 1 heater 2, using a milti-meter check for 220V across those 2 terminals. If you do have power then you have an issue with your heating coil. If you do not see voltage then you have an issue with your controller board. Now if you want to test the heating coil just shut off the unit and unplug it from the wall. unhook those 2 cables for the heater and run an ohms test. If you don't see anything chances are one of the high limit switches went there are 2. You should be able to carefully remove the heating coil and test each switch for resistance and go to your local plumbing supply store to get a new coil or call amana and get the new coils.