How to Replace an Electric Water Heater Element. If you don't seem to have the same amount of hot water available as you had before, you may have a bad heating element in the water heater. Over time, the heating element can become coated with calcium carbonate from the water and its efficiency may reduce. It is a far cheaper repair to replace the element than to buy a new water heater. The removal and installation of a new element is a simple job.
Turn off the power to the water heater. Make sure that everyone knows that you are working on the water heater and they should not turn the breaker on the electrical panel box back on.
Remove the access panel at the top of the water heater using the screwdriver to expose the heating element. There are two elements on the heater, one in the top and one in the bottom. You should remove them both.
Test the resistance of both elements by setting the multimeter to read X1000 and attaching one lead to one of the screw terminals and the other to a heating element mounting screw. If the reading is anything other than infinity, you should replace the element. Test the other element also to determine if it also needs to be replaced.
Attach the hose, close the water inlet valve and open the drain valve to drain the heater. This is necessary before removing the elements from the heater.
Unscrew the terminals from the element and unbolt the element from the heater. Chances are very high that the lower element has a much greater build up of calcium carbonate on the element than the upper element.
Make sure that the heater element that you purchase is the same configuration and model and is rated the same.
Replace the elements in the reverse order and make sure you secure the mounting bolts and terminal screws.
Make sure the drain valve is closed, then remove the hose. Reopen the water inlet valve and allow the heater to refill before turning on the electricity again.
Replace the access panels over the two elements and finally turn on the breaker to the hot water heater.