Replacing a Water Heater
Q: "How long do gas water heaters last?"
How long do gas water heaters last?
—Mark Iliser, Marion, Ind.
Richard Trethewey replies: Generally, both gas and electric water heaters have a 10- to 15-year life span, but that depends on the quality of the water and how well a heater is cared for.
You'll get more life out of yours if you drain the tank periodically to get rid of sludge buildup and remove the tank's sacrificial anode rod at least once a year for inspection. If the rod has dissolved down to its wire core or is completely coated with calcium, put in a new one. A tank without an anode rod will rapidly rust through.
But even if your heater is in good shape, it might be so inefficient that it's not worth keeping. Heating water is the -second-biggest energy expense in most houses, after space heating and -cooling, so it might make sense to replace it with a more efficient heater even before it breaks down. To see how much you might save with a new energy-efficient model, consult the Department of Energy's website. Go to and search for "water heater calculator."