When do you replace water heaters?

Answer 1

Several clues: water leaking from bottom, slow water flow, clunking noises. No hot water from an electric tank could simply be a bad heating element, most tanks have two replaceble elements that are found at hardware stores. A gas hot water tank has a burner that can wear out, or simply the relaceable thermcouple has failed, a new one can be found at hardware stores. Usually, a tank over 20 years old is due for replacement.