Check water heater anode rod

Check the anode rod that protects your water heater tank from corrosion.

Why it matters#

The anode rod sacrifices itself to protect your tank from rust. When it's depleted, your tank starts corroding—and once that starts, failure is just a matter of time.

What you'll need#

Tools#

1-1/16" socket with breaker bar (or pipe wrench)
Ratchet with long handle or cheater bar
Teflon tape

Materials#

Replacement anode rod (if needed—have one on hand)

Steps#

1. Turn off the water heater#

For gas: turn the dial to "Pilot." For electric: turn off the circuit breaker.

2. Turn off the cold water supply#

Close the cold water inlet valve at the top of the tank.

3. Release pressure#

Open the TPR valve briefly to release tank pressure, or open a hot water faucet in the house.

4. Locate the anode rod#

The rod is usually under a hex head bolt on top of the tank. You may need to remove insulation or a cover to find it.

5. Loosen the rod#

Place your socket on the hex head. The rod is often extremely tight—you may need to stand on the breaker bar or use a pipe for leverage.

6. Pull out the rod#

Once loose, unscrew and lift the rod straight up. It's typically 3-4 feet long—you need clearance above.

7. Inspect the rod condition#

Mostly intact with some pitting: Good, reinstall. Less than 1/2" thick in spots: Replace soon. Wire core visible, most material gone: Replace now.

8. Install new rod if needed#

Wrap threads with Teflon tape. Insert the new rod and tighten firmly (don't overtighten).

9. Restore water and power#

Open the cold water supply, let the tank fill, and check for leaks at the anode fitting. Then restore power/gas.

10. Check again in 2-3 years#

Mark your calendar. Water quality affects how quickly the rod depletes.

Pro tips#

Flexible/segmented anode rods are available for tanks with limited overhead clearance
If you smell rotten eggs in hot water, try an aluminum/zinc rod instead of magnesium
A powered anode (titanium with electrical current) never depletes but costs more
Checking the rod is the single best thing you can do to extend tank life

Warnings#

A depleted rod means your tank is now corroding—don't delay replacement
The rod may be very difficult to remove if it hasn't been checked in years—penetrating oil and patience help
Never over-torque when reinstalling—you can crack the tank fitting

If you can't remove the rod yourself (they do get stuck), any plumber can check it during a service call. If your water heater is very old (10+ years) and the rod is depleted, a plumber can help you assess whether to replace the rod or the whole tank.