An electric tank style water heater is by far the most common style in the USA. These water tanks are powered with a 208 - 240 volt circuit due to their increased electric demand. When the water is too cold or too hot, it is most likely due to a malfunctioning thermostat or heating element. These are both relatively easy to replace by a homeowner. Watch the video to see how to diagnose and replace these two parts. You'll need a screwdriver, and a multimeter for diagnosing. You'll need the spare parts from your local hardware store for less than $20 each and a special element wrench for the replacing the heating element for about $7.