To look for faults you will need to use a screwdriver.
How to check water heater thermostat.
The upper thermostat is the primary one that contains the high limit switch and the lower thermostat is used to detect the change in the temperature of the water.
See testing electric water heater elements for more information.
If you want to test a thermostat on an electric water heater you will also need to check the heating element.
2 the tools you ll need.
You ll see a metal plate near the base of the hot water heater.
Either the heater always remains on or it might not get power at all.
I think we can all agree that waking up to take a shower in the middle of winter only to find out that all the water is cold is not the best thing to happen to anyone.
However if the thermostat has defected the heater does not work correctly.
And that s when my tutorial on how to test water heater thermostat will need your attention.
1 how to test water heater thermostat using simple tools available at home.
Remove the metal cover so you can see the water heater s thermostat.
Use a philips head screwdriver to take out the screws holding the metal plate in place.
An electric hot water heater has two thermostats controlling two separate heating elements one in the upper half of the tank one in the lower half.
It allows the water heater to power on off automatically while it gains the appointed heating level.
Usually when the upper thermostat goes bad you will have no hot water at all while a bad lower thermostat makes itself known when there is only a small amount of hot water before the tap water goes cold.
Testing is the only option if you want to determine whether or not one or both of them has failed.
Electric water heater thermostats are a fairly simple devices that can fail from time to time.
4 detach the covers.
If the hot water heater is not working one of the thermostats may be bad.
If the thermostats are okay you need to test the water heater elements.
How to test and replace a water heater thermostat.
You will also need to check the water heater thermostat with digital multimeter tools.
This is important especially as open and grounded heating elements result in inaccurate tests.
You can test them with the power off using an ohmmeter to measure resistance or with the power on using a voltmeter to measure voltage.
Under the plate you ll see the water heater s thermostat and heating elements.
Electric water heaters have one or two elements and each is controlled by a thermostat.
Other than this the thermostat controls the current flowing from one thermostat to another thermostat or from the thermostat to the heater.