Why Is My Water Heater Making a Popping Noise?

That popping or rumbling from your water heater is sediment. Minerals in the water, mostly calcium, settle out and form a layer on the bottom of the tank. Water gets trapped under that layer, the burner fires, and the trapped water flashes to steam and pops its way out through the sediment. The sound itself is harmless. What it says about the tank is not.

What Sediment Does to the Tank

The sediment layer sits between the burner and the water it is supposed to heat, so the burner runs longer to do the same job and the gas bill creeps up. All that extra burn time overheats the steel at the bottom of the tank, which wears out the glass lining inside. Once the lining fails, rust goes to work on the tank itself. On electric models, sediment buries the lower element and burns it out, which is why the shower goes lukewarm.

A Flush Usually Quiets It Down

Hook a garden hose to the drain valve at the bottom of the tank, run it to a floor drain, and drain a few gallons until the water comes out clear. Once a year is right for most homes, twice if you are on a well or have hard water. If the tank hasn’t been flushed in five or ten years, the sediment may have hardened into a crust that clogs the drain valve. That is a job for a water heater maintenance visit, where we also pull the anode rod, the sacrificial part that rusts so the tank doesn’t.

When Popping Means the Tank Is Done

A tank that pops, runs out of hot water sooner than it used to, and is past the ten-year mark is near the end. Rusty or sandy hot water settles it. A flush won’t bring that tank back, and the money is better spent on a new water heater. If you have hard water, add a water softener at the same time. It is the best thing you can do to slow sediment down in the new tank.

Summit Plumbing repairs and replaces water heaters across Springfield, Riverton, Lakeside, Cedar Grove, Maplewood, and Fairview. If yours is popping, leaking, or just plain old, call (555) 123-4567. Ask about our 10% off water heaters special when you do.