Water Heater Making Noise? What Popping, Rumbling and Hissing Mean

Water heaters are supposed to be quiet. When yours starts talking, it is telling you something specific. Here is how to translate.

Popping or Rumbling

This is the most common water heater noise, and it almost always means sediment buildup. Minerals from hard water settle on the bottom of the tank; when the burner heats the tank, water trapped under the sediment boils and pops. Over time this overheats the tank bottom and shortens the heater's life. A professional tank flush usually solves it. If your water heater repair technician finds heavy scale, a water softener installation can prevent it from coming back.

Hissing or Sizzling

On a gas unit, hissing can mean condensation dripping onto the burner — normal during heavy use — or a slow leak dripping onto hot surfaces. Check the floor around the base. A leak from the tank itself means it is time for water heater replacement.

Screeching or Whistling

A high-pitched sound usually comes from water forced through a partially closed inlet valve or a failing T&P relief valve. Both are quick repairs.

Ticking

Pipes expanding and contracting as they heat and cool. Harmless, though adding pipe straps or insulation reduces it.

Humming (Electric Units)

A loose heating element vibrating in the water flow. Tightening it fixes the noise.

When to Worry

Noise plus rusty water, a leak, or hot water running out faster than it used to means the unit is failing. If it is more than 10 years old, replacement is usually the better investment. If you have been thinking about going tankless, see our tankless water heater installation page.

Same-day water heater service is available in Greensburg, Warren, Erie and across Pennsylvania at (888) 809-6756.