How to Repair a Water Heater That's Making Noise

If your electric water heater is making a popping noise, the problem may be with the heater element. Unusual noises such as knocking, banging, hissing or humming in a residential electric hot water heater is usually a result of mineral deposits in the water tank. Mineral deposits due do hard water will coat the heater elements over time, trapping moisture between the coating and element. This moisture reaches a boiling point, causing the unusual noises. Repairing your hot water heater element simply requires cleaning the heating elements, unless they are coated beyond repair in which case they should be replaced. Turn off power to the water heater, and drain the tank. The access covers on the side of the tank can be removed, and then disconnect the wires from the element terminals. Make sure the inlet water valve is closed, and use a hose connected to the drain valve to drain the water until the level is lower than the heater element. Remove the element using a socket or element wrench, and then clean or replace it. If installing a new heater element, make sure the gasket is aligned properly and the element is secure. Connect the element wires back to the element and shut the drain valve. Turn the water inlet supply back on and fill the tank back up. Be sure to monitor for leaks at this point.

If your gas water heater is making noises such as popping, hissing, or knocking, the issue could be a buildup of mineral deposits in the tank. If you have hard or mineral-rich water it can cause minerals such as calcium and lime to coat the bottom of the tank. The moisture between the coating and tank wall boils and creates the unusual noise. To repair your gas water heater, you can flush the tank to rid the buildup. Turn the gas valve to off, or pilot only, and shut off the inlet water valve. Use a hose to connect to the drain valve; open the drain valve and the hot water faucet. Wait until the heater tank is completely empty, and then open and shut the inlet water valve several times to ensure all the water and sediment is flushed. Keep an eye on the water; when it is clear you can close the drain valve and refill the tank.