Inside every tank water heater hangs a metal rod whose entire job is to corrode. The anode rod is more electrochemically active than the steel tank, so rust attacks it first — and when it's consumed, the tank itself starts dissolving. Tanks don't die of old age; they die of anode neglect.
Why Virginia water matters
On moderately hard municipal water — Fairfax, Prince William, Roanoke — an anode lasts four to six years. On iron-heavy well water across Fauquier, Floyd, Bedford and western Loudoun, three years isn't unusual. Softened water consumes anodes faster still. The Shenandoah Valley's hard water adds heavy sediment on top, which is why Valley tanks rumble and die young.
The check
Power or gas off, water off, relieve pressure, then back the hex head out of the top of the tank (an impact driver helps — factory torque is serious). A healthy rod is a rough but continuous cylinder. Replace it when it's mostly consumed, wire-core exposed, or coated in hard calcium chunks.
The math
A rod costs $30–60. A tank replacement runs $1,200–2,000 installed. One rod change at year five routinely pushes a tank past year fifteen. There is no better return in home maintenance.
Smells like rotten eggs?
Sulfur smell in hot water — common on wells — is bacteria reacting with a magnesium anode. Swapping to an aluminum-zinc or powered anode usually ends it without chemicals.