Anode rods protect the water heater tank from the destructive effects of water over the years.
A bad smell may mean that the rod needs replacement. Sometimes the water filtration system will destroy the anode rod very fast and should be replaced as soon as one year. WARNING, THE FOLLOWING DIY HELP INSTRUCTIONS INVOLVE SOME WORK THAT IF DONE IMPROPERLY, MAY RESULT IN SERIOUS INJURY OR DEATH FROM ELECTROCUTION. PLEASE KNOW THE LIMITS OF YOUR ABILITIES.
Many water heaters have anode rods of metals that will permit the water to attack that metal instead of the steel tank. (Some heaters may not have any rods to replace! If there IS one you will see a 1-1/16" nut possibly under a piece of opaque plastic at the top of the tank) Also the Rheem Marathon Water Heater has no anode rod because the heater has no metal in it to destroy! Often called SACRIFICIAL ANODE RODS, these are made of metals such as Magnesium or Aluminum and removing these and replacing them along with a really good flushing of the tank, is a real nice way to extend the life of the heater but use extreme caution because you may:
Break or stress the piping: DO NOT MOVE THE TANK WHEN EXTRACTING THE OLD ROD.
Experience a shock: SHUT OFF THE POWER AND CONFIRM THIS WITH AN ELECTRICAL METER.
Cause a electrical problem: BE CAREFUL THAT THE ELEMENTS IN THE TANK ARE NOT DISTURBED AND THAT WATER DOES NOT GET ONTO THE EXTERNAL CONNECTIONS.
Cause a flood. CONFIRM THE WATER IS COMPLETELY SHUT OFF.IF YOU FEEL YOU NEED HELP, CALL ME, KEN ANDERSON FOR REPLACEMENT OF THE ANODE ROD