How to Troubleshoot the Water Heater Electric Thermostats

Place both prongs of the multimeter on the two contact screws on the face of the heating element below the thermostat. If the needle remains at zero, replace your thermostat.Siemens Ultrasound Probe If the multimeter needle reads between 220 volts and 240 volts, check your lower thermostat.
Turn the water heater off at the main breaker panel.  Set the dial on the upper thermostat to the lowest temperature setting and set the dial on the lower thermostat to the highest temperature setting. Turn on the water heater at the breaker panel.
Place both prongs of your multimeter onto the two contact screws on the face of the lower element beneath the lower thermostat.Siemens Ultrasound Probe If the needle on your multimeter remains at zero, you should test the lower thermostat.

Touch one probe of your multimeter to the top contact screw on the lower thermostat. Touch the other probe of your multimeter to any metal on the water tank. The needle on your multimeter should read between 110 volts and 120 volts and you should continue to the next step. If the needle does not register a reading, the upper thermostat isn't sending electricity to the lower thermostat. Replace the upper thermostat.
Touch one probe of your multimeter to the lower contact screw on the lower thermostat. Touch the remaining probe of your meter to the metal of the water tank. Your meter should read between 110 volts and 120 volts.Siemens Ultrasound Probe If the needle does not register a reading, replace the lower thermostat.

Turn off the electricity to the water heater. Reset your thermostats to your previous temperature settings. Snap the thermostat covers back on to the thermostats. Replace the insulation over the thermostat and reattach the access doors.