How to Open a Hot Water Heater

Shut off the power for the water heater. Go to the main circuit breaker and identify the switch that controls the heater. Switch it to the "Off" setting. Stick a piece of tape across the switch so no one turns it on while you are working.

Turn off the gas supply, if you have a gas water heater. Most gas heaters are connnected by a flexible hose back to the gas supply valve. Rotate the valve to cut the gas supply.

Connect one end of a garden hose to the hose bibb at the bottom of the water heater. Tighten the coupling on the hose over the threads at the end of the bibb. Run the other end of the hose to a nearby drain or out into a nearby yard.

Turn off the cold water supply valve for the hot water heater. These are usually located somewhere near the top of the heater.

Go inside the house and turn on the hot water tap nearest the water heater. Raise the water relief valve on the side of the water tank to the open position. Opening both of these valves will equalize the pressure inside the tank and allow the water to drain more easily. Open the handle on the hose bibb and allow the water inside the tank to drain.

Locate the heater panels on the side of an electric water heater. Remove the screws holding them in place with a screwdriver and set aside. Carefully push aside any insulation on the inside of the tank so you can see the rear of the heating elements. There are usually two heating elements, one at the top and one at the bottom of the tank. Unplug the wires from the terminals on the end of the elements. Unscrew the bolts holding the elements in place with a socket wrench to gain access to the water tank.

Remove the garden hose from the hose bibb. Grasp the base of the bibb with a wrench and turn the whole bibb counterclockwise until it unscrews off the outlet pipe. Access the inside of the water heater with a cleaning tool, if needed.