How to Replace a Water Heater Anode Rod

SANTA CRUZ — One of the most crucial components of a water heater is its sacrificial anode rod. Made from magnesium, aluminum or aluminum/zinc alloy, this rod serves one function: to attract and absorb corrosion and divert it away from the water heater tank (hence the qualifier “sacrificial”). However, even though it protects a water heater from rust, an anode rod can stop working after years of sustained subjection to corrosive activity, which is why it’s important to replace it on a regular basis (every four to five years).

Fortunately, this is a maintenance task you can perform yourself. After shutting off the water to your water heater and disconnecting the supply line, use a pair of pliers to unscrew and remove the anode rod. Typically, the hexagonal head of the rod will be visible at the top of the water heater (if you have trouble locating it, consult your owner’s manual). Once the old rod is out, you can drop in the new one and tighten it in place with your pliers before reconnecting the supply line and turning the water back on.

Since corrosion is a common cause of water heater failure, anode rod replacement is just as important as annually draining and flushing the tank. Most notable is the effect on longevity—proactive anode rod replacement can substantially extend and even double a water heater’s expected lifespan.