How To Test Your Electric Water Heater Thermostat

You will need a flathead screwdriver and a multimeter to test your unit's water heater thermostats. With those tools at hand, follow the steps below:

1.Power off – Turn off your water heater's breaker on your electrical panel.

2.Remove panels – Use a flathead screwdriver to remove the upper and lower thermostat access panels. A layer of insulation should cover the thermostats, so fold it out of the way and secure it temporarily with tape.

3.Upper thermostat test #1 – Turn the upper thermostat to its maximum temperature using your screwdriver. Adjust the multimeter to RX1. Place a one-meter probe on the bottom left terminal. Place the other meter probe on terminal screw #1 just above the #2 terminal. You should get a reading of 0. The thermostat is faulty if you don't get a reading at all.

4.Upper thermostat test #2 – Turn the upper thermostat temperature to the lowest setting. You should hear it click off. Place one probe on terminal #1. Place the other probe on the bottom right terminal screw (#4). You should get a reading of 0. The thermostat is faulty if you don't get a reading at all.

5.Lower thermostat test – The lower thermostat is easier because it only has two terminals. First, use your screwdriver to turn the temperature up. (The upper thermostat must be clicked off, which should have been achieved in step #4.) Place a meter probe on each of the terminal screws. You should get a reading of 0. The thermostat is faulty if you don't get a reading at all.

When you are finished, adjust the thermostat temperatures back to normal, replace the insulation, and screw the panels back on.