Why is my water heater making noise?

Normal sounds

Rheem lists several sounds as normal if they're quiet, brief and regular: ticking or clicking from pipes and heat traps expanding, humming from electric elements while they heat, gurgling after heavy use, and soft ignition sounds on gas models.

Popping, rumbling or boiling

This is the classic sediment noise. Rheem calls sediment the most common cause of popping or rumbling in tank heaters. Bradford White explains that minerals settle on the tank bottom, and when the burner fires, water trapped under that crust bubbles through it.

Hard water makes it worse. A flush can help a younger tank. On an older tank that's popping loudly, the sediment may be packed hard, and it's often a sign the heater is near the end.

Hissing or singing on an electric heater

Bradford White says electric heaters often develop singing or hissing as lime and scale build up on the heating elements. Cleaning or replacing the elements fixes it. Where water is hard, a softener helps prevent it coming back.

Sizzling, hissing or dripping: act now

Rheem warns that hissing, sizzling or dripping sounds can mean an active leak, such as water dripping onto a hot burner on a gas heater or a leaking element gasket. Turn off the power or gas to the heater, stop using it, and have it inspected.

Screeching or whistling

High-pitched sounds usually mean water squeezing through a restriction, like a partly closed valve. Make sure the cold supply valve is fully open. If the sound continues, have it checked.

Banging or knocking

Rheem notes that banging often comes from the plumbing, not the heater. It's water hammer: flowing water stops suddenly, and the pipes shake. Pipe straps, water hammer arrestors or lower water pressure can fix it.

Local pages mentioned

• Millersville, PA
• Kuna, ID