An electric water heater contains one or two heating elements similar to what you might find in your oven, except that they’re short and narrow. These electric elements can become laden with lime and mineral deposits that reduce their effectiveness or cause them to overheat and short out.
To clean your electric elements, turn off the power to the water heater and then follow these steps:
Drain the tank by turning off the cold-water valve at the top of the water heater, attaching a garden hose to the drain valve at the base of the water heater, and opening the drain valve.
To facilitate draining, open a hot-water faucet somewhere in the home.
After the water heater empties, use a screwdriver to remove the access panels to the elements.
Depending upon the number of elements, one or more access panels will have to be removed. You may need to move a piece of insulation to expose the element.
Using your screwdriver, remove the elements and any electrical wires that power them.
Elements are generally attached with a series of bolts, or they have a threaded base that screws directly into the tank.
Clean the removed element, using a solution of vinegar and water or sodium carbonate and water (2 tablespoons of vinegar or 2 tablespoons of sodium carbonate in 1 quart of hot water) and a scouring pad.
If an element has begun to corrode, replace it with a new one. Many different element types and styles are widely available; simply take the old one to the hardware store and find a match. Cooler-than-normal water, sporadic hot water, and a short supply of hot water are all telltale signs of a corroded element.
Reconnect the wires and refill the water heater.
To refill the water heater, close the drain valve and turn the cold-water supply valve on, making sure that the hot-water faucet farthest from the water heater is left open to express all the air from the system.
Check for leaks around the elements and then replace the insulation and access panels and turn on the power.
Hard water and an electric water heater are a disastrous combination. You will forever be cleaning and replacing electric elements. Consider installing a water softener if you have an electric water heater.