A failed electric hot water system thermostat is the common reason why you’re not getting any hot water from your electric water heater. The good news is that replacing a thermostat isn’t difficult at all. You won’t even have to drain the tank.
Here’s a procedure that applies to either the upper or lower thermostat on your water heater. You’ll need a #2 Philips screwdriver, a flat blade screwdriver, and a voltmeter.
New Electric Hot Water System Thermostat
First, be sure the new thermostat is the same type of thermostat that you’re replacing. Keep in mind that the upper thermostats are usually not the same as the lower thermostat. Refer to our website for ordering the thermostat for your specific water heater. First, turn the power off to the water heater at the circuit breaker. Then remove the cover panel and insulation to expose the thermostat.
Remove the reinforcing bracket and throw it away. You’ll also need to remove the plastic protective cover over the thermostat. Using a voltmeter, verify that power has been disconnected. There should not be any power.
Disconnect the thermostat wires. Tag the wires before removing them from the screw terminals to eliminate incorrect wiring later. You could also take up a full digital snapshot of the wiring for reference.
Remove the thermostat by lifting it out of the retaining bracket. Be careful not to pull too hard. Breaking the retaining bracket will require the entire water heater to be replaced. Replace the old thermostat with an identical new one.
Be sure the back of the thermostat is pressing tightly against the tank because that affects the accuracy of the temperature reading. Rewire your tag leads to the proper screw terminals.
Double check to be sure your wire connections are correct and that they’re firm and tight.
And replace the plastic protective cover. Finally, adjust the new thermostat so the water temperature doesn’t exceed 120 degrees Fahrenheit.
Replace the insulation and cover panel, and you’re done. Turn the power back on to the water heater at the circuit breaker. And about an hour, you’ll have plenty of hot water again.