Although not very well known, sacrificial anode rods are often the most important factor in the health of your hot water heater tank. Most often made of aluminum or magnesium, these rods have a steel wire core and screw into the top of hot water heater tanks. The sacrificial anode prevents the inside of the hot water heater tank from rusting. Replacing a worn-out sacrificial anode rod can extend the life of your hot water tank.
Things You'll Need
- Long wrench
- Pipe wrench
- Ratchet wrench
- Socket (1 1/16 inches)
- Penetrating oil (such as Liquid Wrench)
- Screwdriver (optional)
- Power or impact wrench (optional)
- Drill (optional)
- Tin snips (optional)
- Wire cutter (optional)
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Shut off the electricity or gas to the water heater. Shut down the water supply. Open a hot-water faucet on the same water line to relieve pressure within the water heater. If water continues to run, your water is not shut off. Drain a little water from the tank until the level goes down a few inches.
Examine the top of the water heater for the top of the anode rod (spud) or connecting hardware. Some water heaters, particularly those with longer warranties, have multiple anodes. Look for the sacrificial, or corroding, anode. It may be under a cap, about halfway in toward the center (not on the outside edge). The anode may be under a pink-top nipple. If you don’t see a spud or connector, remove the top of the water heater. (Very occasionally, the anodes are under a sheet-metal cover that has been foamed into place, requiring you to drill through the top—but not far—and poke around with a screwdriver to find the anodes.)
Apply penetrating oil generously to the connecting nut or threads of the anode rod, which is hanging vertically from the top of the water heater. Allow the penetrating oil time to work.
Loosen the anode carefully with a wrench. Corroded anodes are brittle.
Remove the anode. If there isn’t enough clearance to withdraw the anode straight up, carefully bend it into a curve while pulling from the water heater.
Disconnect the water heater from its plumbing and gas or electric connections if you cannot bend the anode enough to remove it without cutting or breaking. Drain enough additional water from the water heater tank so you can tip it sideways. Remove the anode. (Or, consider pulling the anode out a little at a time, securing its position, cutting above that point, and repeating until the anode has been removed completely.)
Return the water heater to a secure, upright position. If you won’t be performing additional work on your water heater at this time, put any top in place. Reconnect the water and gas or electricity connections. Restore the water supply and the electricity or gas to the water heater. Turn off the open hot-water faucet.