Perhaps the most common problem associated with electric water heaters involves the heating elements. Assuming that both elements have been replaced, a persistent problem can likely be traced to an electrical supply problem or to the thermostat. If the elements have been replaced, the thermostat must be reset. If resetting the thermostat does not solve the problem, the thermostat is most likely defective.
Checking the Electrical Supply
It is common to forget to restore the power supply once the elements have been replaced, and this is very easy to correct. Make sure that the heater's electrical supply cord is plugged into a working outlet. Also check the appropriate circuit breaker within the breaker box. Keep in mind that it will take some time for the heater to produce hot water.
Resetting the Thermostat
As with the heating elements, the thermostat is located behind the access panel on the side of the tank. Turn the power to the heater off before removing the panel. The thermostat will likely be concealed behind insulation so pull the insulation aside to access it. Note that the thermostat has a red button on its face. Press the red button to reset the thermostat. This is also a good time to check the water temperature setting. Locate the temperature adjustment screw on the thermostat and turn the screw to between 120 and 125 degrees Fahrenheit.
Removing the Thermostat
Turn the power off before touching any of the thermostat wires. As a safety measure, confirm that the heater is not receiving power by touching the top two screws on the thermostat with a circuit tester. To avoid confusing the placement of each wire, wrap each one with masking tape and write down the wire's position in relation to the thermostat on the tape. Note that each wire is secured to the thermostat with a single screw. Loosen the securing screws and pull the wires off of the thermostat, then lift the thermostat out of its mounting clips.
Installing the Thermostat
Snap the new thermostat into place within its mounting clips before attaching the thermostat wires. It will likely be necessary to loosen each securing screw to allow enough room for the wires to hook to the screws. Position each wire against its securing screw, taking care not to mix up the position of the wires, then tighten the securing screws over the wires. Press the red button to reset the thermostat and set the temperature to between 120 and 125 degrees. Carefully fold the insulation over the thermostat then reinstall the access panel and restore the power.
- "Ten Pound Books: Home Repair Guide"; Creative Publishing International; 2007