Why Is Your Water Heater Making Noise?

Sound-by-sound diagnosis

Popping or rumbling

Sediment baked onto the burner pad. Steam pockets pop as water flashes through the crust. The #1 noise we hear in Albuquerque, and the easiest to fix: a full sediment flush. Cost: $189 with a yearly tune-up.

Ticking or tapping

Heat traps in the supply nipples or thermal expansion in the pipes. Usually harmless. If it's loud and getting worse, the heat traps may be failing. Replacing them runs $135 to $195.

Hissing or sizzling

Water dripping onto the burner from above (an internal leak), or condensation evaporating off the burner on a high-humidity day. The first means replacement. The second goes away when the unit warms up.

Screeching or whistling

Restricted flow, usually a partially closed inlet valve, a kinked supply line, or a clogged faucet aerator pulling air. Open the valve fully or check the supply lines.

Banging from the pipes

Water hammer when the unit cycles. Add a hammer arrestor at the tank or near the affected fixture. $145 to $215 installed.

When the noise means real trouble

If popping is persistent (months, not just after a recent flush), if you hear water dripping inside the cabinet, or if you smell gas while any noise is happening, stop using the unit and call us.