Test Upper Thermostat Electric Water Heater
Check the power supply of the thermostat.
Test upper thermostat electric water heater. The reading on the multimeter should be zero. While the other is found right on the bottom. Start by checking the thermostat terminals for the supply of power. Before you proceed further with the process of testing the heater thermostat take a screwdriver and the multimeter.
One should be sitting on the top of unit 1. You will also need to check the water heater thermostat with digital multimeter tools. Using the multimeter connections touch the top to legs at the same time. If you get the reading of 240v on terminal 1 and terminal 3 then the power is on but if you get no readings then the power is off.
This is important especially as open and grounded heating elements result in inaccurate tests. The meter should read 0. The upper thermostat has two functions. Use the screwdriver to set the lower thermostat to the highest setting.
Before handling anything on the thermostat use a multimeter to confirm the power is off to the water heater. Test the water heater thermostat. First it allows the upper element to heat the water in the top of the tank. Connect the multimeter pin ends on point 1 2 as shown in the picture below.
Your water heater usually has two elements and two thermostats. In this case also check the current at the high limit switch. Leave the upper thermostat in the lowest setting and test the lower thermostat. If you want to test a thermostat on an electric water heater you will also need to check the heating element.
The structure of an electric water heater is pretty simple. If you have a voltage stick you can use that as well. To look at the faults in the upper thermostat you need to turn off the lower one. If the water is cold the multimeter will point near zero.
Testing the water heater thermostat involves the checking of the heating element also. When this water is hot enough it shuts the upper element off. To look for faults you will need to use a screwdriver. If the opposite thing happens that means your thermostat has defected.
And when it comes to thermostats the device uses two of them generally. The lower thermostat has only two terminals.