Inspect and Replace Water Heater Anode Rod

Turn off water and power to the heater. Locate the hex-head anode rod (usually under the top of the heater, often under the plastic cover). Use a 1-1/16 inch socket to unscrew it. If it's less than 1/2 inch thick or heavily corroded, replace it ($25–$50 at any hardware store). The anode rod 'sacrifices' itself to protect the steel tank from corrosion. Without a working rod, a tank can rust through and fail in as few as 5 years; with it, 15–20 years. Replacement takes 15 minutes.