Popping or rumbling sounds
This is the most common water heater noise, and it almost always means sediment. Minerals in your water settle at the bottom of the tank over the years, and as the burner heats the water underneath that layer, steam bubbles form and pop through it — that's the rumbling or popping you hear. A flush can clear light sediment, though a tank with years of buildup may never go fully quiet again.
A high-pitched whining or screeching
This usually points to a partially closed shutoff valve or a narrowing in a pipe fitting, which forces water through a smaller opening than it's meant to pass through. It's worth checking the valve on top of the tank first, since that's an easy, no-cost fix if it's simply not fully open.
Ticking sounds, especially right after the water turns off
Ticking is typically just the pipes expanding and contracting as hot water moves through them — normal thermal movement, not a sign of damage. If it bothers you, pipe insulation can quiet it down.
A loud bang or clunk
Known as water hammer, this happens when a fast-closing valve (often on a washing machine or dishwasher) sends a shockwave back through the pipes. It's not usually caused by the water heater itself, but it is worth mentioning when you call, since it can sometimes be fixed with a water hammer arrestor.
A noisy water heater that's also showing rust-colored water, a leak at the base, or inconsistent temperatures has moved past "worth a flush" into "worth a look." Our water heater repair team diagnoses the actual cause rather than guessing from the sound alone.