Most home buyers ask about the roof, the furnace and the sewer line. Far fewer ask about the water heater's anode rod, a small metal part that does quiet work for the tank. If you are looking at a house this season, a question or two about it is worth asking before you sign.
What the rod does
Most storage water heaters have a steel tank lined with glass. That lining can have tiny gaps, and hot water is a corrosive environment. The anode rod, usually made of magnesium or aluminum, is designed to corrode first so the steel tank does not. Think of it as a sacrificial part. Once it is mostly used up, the tank itself starts to take the damage, and leaks often follow.
Water chemistry matters here. Acidity and certain dissolved minerals can speed up corrosion, so two houses with the same heater model can see very different rod lifespans. That is why the age of the heater alone does not tell you the whole story.
Why the question matters at a sale
A depleted rod does not announce itself. The heater may keep producing hot water for a long time while the tank quietly wears. The rod sits inside the tank, so it usually has to be pulled out to be checked. Inspection scopes vary, so ask your inspector directly whether they look at the anode or only the heater's age, venting and pressure relief valve.
Ask the seller whether the rod has ever been checked or replaced, and when. If the seller cannot say, treat that as information too. A missing service record does not prove a problem, but it does mean you are buying the unknown.
Questions to ask before you sign
- How old is the water heater, and is there a service record?
- Has the anode rod ever been inspected or replaced, and by whom?
- Is the unit a storage tank or a tankless model? Tankless units generally have no rod of this kind, so the question changes.
- Is there any water on the floor around the base, or rust staining on the tank?
A quick check during a walk-through
Look at the base of the heater for corrosion, rust stains or moisture. Note the age from the data label. None of this replaces a licensed plumber's assessment, but it tells you where to press. A plumber can test the rod and tell you whether it needs replacing now. Replacing a rod is often a much smaller job than replacing a tank, so a worn rod found early is a manageable repair, while a leaking tank usually means a new heater.
Where a water test fits in
Because water chemistry affects how fast a tank corrodes, the rod question and the water question meet. If you do not know what your supply carries, start there. Jones Air & Water offer free in-home water tests, which can give you a baseline before you commit to a house and the equipment inside it.
The trade-group headline, in context
Leadership news in the water sector rarely changes what happens in a basement. Water Finance and Management reported that Dan Hartnett, who had been serving as interim chief executive of the Association of Metropolitan Water Agencies, has been "selected to serve as its CEO on a permanent basis" effective Nov. 1, 2026. That is a useful update for people who follow the industry, but it does not change the condition of the heater in any house on the market. Your own checklist still starts at the tank. You can read the original item at Water Finance and Management's report on the AMWA leadership selection.
The bottom line
The anode rod is inexpensive to check and easy to overlook. Ask about it during the offer stage, have the heater looked at during the inspection, and treat the answers as part of the house's true condition. A few minutes of questions can save you from buying a leak you could have seen coming.