How To Test Water Heater Thermostat

If you want to test a thermostat on an electric water heater, you will also need to check the heating element. This is important, especially as open and grounded heating elements result in inaccurate tests.

To look for faults, you will need to use a screwdriver. You will also need to check the water heater thermostat with digital multimeter tools. Now let us get started with the following steps on how to test a water heater with multimeter.

1.Move to the thermostat terminals and check if it is supplied with power. If it is, you will have a reading of 240V on terminals 1 and 3. But if there is no reading, check its power source. Also, check for current on the high limit switch.

2.Disable the lower thermostat by rotating its dial to the least setting. Next, turn up the temperature of the upper thermostat to look for faults.

3.Place the prongs of the multimeter on the terminal 1 and blue wire of the heating element. This will help you detect if power is supplied between the upper heating element and blue wire.

4.If the tool reads 240V that means there is power on the setup. Next place the prongs on terminal 2 and the blue wire of the heating element. But if there are no readings that means the thermostat is faulty.

5.Move to the lower thermostat on the heater. Adjust the dial on the upper thermostat to the minimum setting while you set the other thermostat to the highest level.

6.Head back to the terminal 1 and red wire of the bottom heating element. Place a probe on both of them to detect power. If it reads 240V, then there is power in the setup.

7.Place the probes on terminal 2 and red wire of the bottom heating element. If you have no readings, then you will need to swap the thermostat for a new one.