Replacing a Water Heater Thermostat
A faulty thermostat or high-temperature cutoff in an electric water heater can allow the water in the tank to heat well past recommended temperature ranges. The same thing can happen if the high-temperature cutoff is defective. Since the thermostat and high-temperature cutoff are usually found in one unit, replacing both elements simultaneously saves time and money.
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Step One
First, turn the power off. Then, disconnect the power to the water heater by turning off the circuit breaker at the main panel. If you haven’t mapped your breaker box, shut off all the breakers one at a time until you find the heater switch. Be sure to mark the breaker for future reference.
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Step Two
Remove the access panel. Use a screwdriver to remove the screws and then lift off the panel.
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Step Three
Label the wires and terminals. Before removing the thermostat, number the wires and terminals. This will help you reconnect each wire to the proper terminal.
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Step Four
Lift out the thermostat. Disconnect the old thermostat from the mounting clip and lift it out. Replace it with a new thermostat of the same model.
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Step Five
Connect the wires. Install the new thermostat to the mounting clip and then reconnect the wires in the order that you numbered them.
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Step Six
Restore the system. Set the thermostat to the manufacturer’s recommended temperature. Make sure the tank is full. Restore power to the water heater and the circuit breaker. Press the red “reset” button on the thermostat.
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Step Seven
Replace the access panel. Replace insulation and reinstall the access panel.