One is at the top and the other is at the bottom.
Water heater thermostat location.
An upper and a lower located under two control panels.
Both of them control their respective heating elements.
Gas water heaters use a different type of thermostat system.
An electric water heater has one or two thermostats depending on the gallon size of the tank.
The one on the right in the picture above t stat is the actual thermostat that controls the heat of the water.
Each thermostat has two wires attached to it.
Adjusting an electric hot water heater temperature thermostat setting is a little more involved but still relatively easy.
On most gas water heaters the gas control valve which includes both a thermostat and a heat limiting device are located on the outside of the unit near the bottom.
You will find two thermostats in your water heater.
Turn off the circuit breaker to the water heater.
An electric water heater has two thermostats located under access panels on the side of the tank.
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.
It can be identified as the component with the controls for temperature and the pilot light.
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.
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.
The majority of electric water heaters have two thermostats.
When you open the door to your water heater you should see a rectangular black section of insulation like the one in the photo below.
2 remove the access cover panels located on the side of the tank.
Electric water heaters have one or two elements and each is controlled by a thermostat.
If the hot water heater is not working one of the thermostats may be bad.