Water heaters aren't silent, but new or louder noises usually mean something has changed inside the tank.
Popping or rumbling
This is the most common noise, and it's usually sediment. Minerals settle at the bottom of the tank, trap water beneath them, and that water pops as it boils through. Hard water — common across much of Southern California, the Inland Empire and the Central Valley — speeds this up. Flushing the tank helps; a water softener slows it down.
Hissing or sizzling
On a gas heater, hissing can be water dripping onto the burner — which may mean a leak. On electric heaters, it can be sediment around the element. Check for water around the base.
Ticking or tapping
Usually pipes expanding and contracting, or a heat trap nipple. Often harmless.
Screeching or whistling
A partially closed valve or a relief valve under pressure. A relief valve that discharges should be checked right away.
Repair or replace?
If the tank is under about 10 years old and not leaking, water heater repair and a flush often fix it. If it's older, leaking or the noise comes with rusty water, plan for water heater replacement — or consider tankless.
Get service in Anaheim, Fontana or Stockton.
FAQs
Is a noisy water heater dangerous?
Popping from sediment is usually not immediately dangerous, but it shortens tank life. A discharging relief valve should be checked right away.
How often should a water heater be flushed?
About once a year, more often with hard water.
Will flushing stop the noise?
It often helps if sediment hasn't hardened.