The emergency call we get most often is a water heater that has split its tank and emptied forty gallons across a garage floor. Almost every one of them had been signalling for months. Tanks very rarely fail out of nowhere; they fail after a slow process that is easy to see if you know what you're looking at.
The first sign is noise. A rumbling or popping sound when the burner fires is sediment that has settled on the bottom of the tank — water trapped underneath it boils and forces its way through. That sediment layer insulates the steel from the water above it, so the burner runs longer and the tank bottom runs hotter than it was designed to. It is both a symptom and an accelerant.
The second is rusty hot water. If the hot side runs discoloured and the cold side runs clear, the corrosion is inside the tank, not in your supply lines. That usually means the anode rod — a sacrificial metal rod that corrodes so the tank doesn't — has been consumed. Replaced early, an anode rod is a cheap service item. Left too long, the tank itself starts to go and nothing brings it back.
The third is moisture. Any damp ring, mineral crust, or drip at the base of the tank is a tank that has already begun to fail. A weeping seam does not reseal itself; it opens. If you see water under a heater that is more than eight years old, you are on borrowed time and you should be choosing a replacement rather than waiting.
The fourth is age plus performance. Most tank heaters last eight to twelve years. If yours is in that range and it has started running out of hot water sooner than it used to, or the pilot won't stay lit, the economics have already tipped. Replacing a heater on your schedule costs the heater. Replacing it after it lets go costs the heater plus the drywall, the flooring, and whatever was stored beside it.
One more thing worth knowing: California code requires seismic strapping, a drip pan with a drain where the location calls for it, and a correctly run temperature and pressure discharge line. A surprising number of the heaters we replace were installed without them. When we swap a unit, those go in as part of the job, not as an upsell.
Advantage Build and Design installs and repairs tank and tankless water heaters across Los Angeles County, the San Gabriel Valley, Orange County, and the Inland Empire — 24 hours a day. Call (626) 404-4046.