Hot water heaters generally have two heating elements. One heating element is located at the bottom of the hot water tank, and one heating element at the top of the hot water tank. The heating elements that heat the water inside of the hot water tank will wear out over time and need replacing. When one element burns out the second heating element will follow shortly after so replacing them both at the same time will prevent you from doing this twice.
Things you will need
New heating elements
Turn off the power supply to the hot water tank at the main electrical box of the home. If your breakers are not marked, turn off the main breaker to the home.
Turn the water supply off to the hot water tank. The shut off valve is located on the bottom of the hot water tank. Turn the handle on the shut off valve clockwise until the handle is tight.
Remove the insulation from around the outside of the hot water tank. Remove the heating element cover plates. There is one plate located at the top of the tank and one at the bottom of the tank. Use a screwdriver to remove the screws located on each cover plate.
Open the hot water valves on the bathtub and the sink. This allows the hot water to drain out of the hot water tank before removing or loosening the elements.
Loosen the screws on both of the heating elements. Remove the contact wires from the heating elements. Let the water flowage stop from the faucets before moving on to the next step.
Loosen the heating elements with an adjustable wrench. Turn the elements counter clockwise until the heating elements remove. Repeat this procedure for the other heating element.
Slide the new gasket onto the new heating element making sure to seat the gasket against the threaded end of the element. Turn the heating element until it has become hand tight and then snug the heating element tight using an adjustable wrench. Repeat for the remaining heating element. Reconnect the contact wires to the heating elements with the screws provided with the new elements.
Turn the water supply to the on position to refill the tank. Wait for the entire tank to refill before restoring the power to the hot water tank. This prevents the new elements from burning out. With the hot water tank full, turn the power back on. It takes about 20 to 40 minutes before your hot water tank will contain hot water.
Reinstall the element cover plates to the outside of the hot water tank. Then install the insulation cover around the outside of the tank.
Replacing hot water heating elements is a common household repair.