How to Fix a Leaky Heating Element

Disconnect the electrical power to the water heater to prevent electrical shock. Failure to disconnect the power can cause any working, or non-leaking heating elements to burn out. In practice, the power to the water heater should remain off whenever the water tank is empty or below recommended levels.

Close off the cold water valve that feeds the water tank. Cold water lines run into the top of the tank with a valve that turns the flow on and off. Use a garden hose to empty the hot water tank into an outdoor drain or other desired location. Attach the garden hose to the tank's drain valve located at the bottom of the water tank. Turning the lever on the valve allows water to flow out of the tank. Before draining the tank, ensure water temperatures have cooled down enough to avoid being scalded. Open a hot water tap at any sink, tub or drain near the tank location to allow air into the plumbing system. This will help to drain water from the bottom portion of the tank.

Disconnect any wires that run to the heating element before attempting to remove it. The heating element appears as a large square knob on the side of the tank. The knob should have a "heating element" inscription or label on its front. When unscrewed, the element appears as a long metal coil. On some water heater models, the heating element screws into a large opening, so you may need a large socket wrench to remove the element. The water heater manual provides specifications for the type of replacement element needed, which you can purchase ahead of time, though taking the faulty element into the store can help ensure a proper fitting replacement element.

Clean out the opening where the heating element goes with a toothbrush or other medium-hard bristled brush. Water heaters typically have an upper and lower heating element. If replacing the lower heating element, any scale buildup along the tank bottom should be removed at this time. Insert a vacuum hose through the opening left by the element so that it touches the tank bottom. Vacuum out the bottom surface of the tank.

Apply a pipe thread sealant or Teflon pipe dope to the threads inside the heating element opening. Apply the same to the threaded portion of the new heater element. These materials help produce a clean electrical connection between the heating element and the water heater.

Reinsert the heater element into the water tank compartment. Reattach the electrical wires that go to the heater element. Specific pole-to-wire attachments don’t matter, so either wire can attach to either pole on the element. Turn off any hot water taps in the home that were turned on to provide air pressure. Remove the garden hose from the tank and close the drain valve. Re-fill the water tank by turning on the cold water valve at the top of the tank. The tank will fill quicker if the cold water feeder valve is opened prior to opening the nearest hot water faucet. Once the tank is filled, restore electrical power to the water heater unit.