Step 1
Cut the heating element for the hot water heater. In a gas heater, shut off the gas supply by turning the gas heating valve on the supply pipe or hose. Most valves will have an indicator or stamp showing which direction the valve should be turned to cut the supply. For an electric water heater, turn off the power for the heater at the main circuit breaker. Place a piece of tape over the heater switch in the breaker so it isn't turned on accidentally.
Step 2
Turn off the cold water supply inlet at the top of the tank. This may be labeled, or the valve could be color coded with a blue tint.
Step 3
Locate the hot water tap nearest to the Whirlpool hot water heater. Turn this tap to the open position.
Step 4
Connect a hose to the drain at the bottom of the Whirlpool heater. Tighten the coupling on the end of the hose to the drain outlet. Open up the relief valve on the side of the water heater. Run the other end of the hose to a floor drain or out into the yard.
Step 5
Open the tap on the water heater drain valve. Allow the water to run out of the heater for approximately one minute. Close the tap.
Step 6
Unscrew the hex nut at the top of the water heater with a wrench or pair of pliers. Pull the anode rod out of the Whirlpool heater by the next nut.
Step 7
Wrap the threads on the new anode rod with plumber's tape. Insert the anode rod into the Whirlpool heater. Thread the hex end into the top of the heater. Tighten with the wrench or pliers.
Step 8
Close the relief valve on the Whirlpool. Turn on the cold water supply valve.
Step 9
Restore the electrical or gas supply for the Whirlpool heater. You may need to manually relight the pilot light in older Whirlpool gas water heaters.