Why Is My Geyser Making a Noise?

A geyser that’s suddenly making popping, banging, or rumbling sounds isn’t something to ignore — it’s usually telling you something specific is going on inside the tank.

Popping or cracking sounds

This is the most common one, and it’s almost always sediment. Over time, minerals in the water settle at the bottom of the tank and harden. As the element heats water trapped under that sediment layer, small pockets of steam form and burst, creating a popping sound. It’s more of an efficiency and lifespan issue than an immediate danger, but it does mean the element is working harder than it should.

Rumbling or humming

A build-up of sediment on the element itself can cause a low rumbling or humming noise as the water struggles to circulate properly around it.

Whistling or hissing

This is more often related to the pressure relief valve or a partially closed inlet valve restricting water flow, rather than the tank itself.

Ticking after switching off

Some ticking as metal components expand and contract with temperature changes is normal and not a cause for concern.

Should you worry?

Occasional minor sounds are common in older geysers. Loud, frequent, or worsening noises are worth having checked — sediment build-up left unaddressed shortens a geyser’s lifespan and increases the chance of element failure. A service to flush the tank and inspect the element is usually all that’s needed if caught early.