Sacrificial anode rods are installed through the top and are relatively easy to access on most conventional residential water heaters. The majority of tank manufacturers locate it within its own port just off centre of the top plate. This style uses a rod with a hex-head end cap - telltale signs of its location can usually be seen by looking over the top plate.
Many older units have it located at or above the top cover while it is located deeper down on most newer units due to thicker insulation around the vessel. Sometimes they are exposed and other times they are covered with a plastic plug or even covered over with insulation. Either way, this style of anode is removable on its own without disturbing the hot water line connection.
In units where a second rod is employed to prolong water heater life and provide a longer warranty, a secondary anode may be installed in the hot water line (a combo rod) as described below.
Where Is the Sacrificial Anode Rod Located?
Other manufacturers install their primary rod in the hot water outline line and manufacture it as part of the outlet nipple. This style of sacrificial anode is referred to as a combo rod and requires disconnection of the hot water line to remove/inspect/replace the anode rod. It’s a little more work, and takes a little more time, but its always worthwhile to check and replace if necessary. This configuration also forms the secondary rod on certain models as described above.
