Popping and rumbling
The most common water heater noise is popping or rumbling. It is caused by sediment, mainly calcium and magnesium from hard water, settling at the bottom of the tank. Water trapped under the sediment boils and bursts through, creating the popping sound. Much of Texas has hard water, so this is very common.
Flushing the tank can reduce the noise and improve efficiency. Heavy sediment, though, can mean the tank is aging. Our water heater repair team can flush it and assess its condition.
Hissing or sizzling
Hissing from an electric water heater can come from sediment around the heating elements. On a gas heater, sizzling can mean water is dripping onto the burner, which may point to a leak. Check for moisture and call a plumber.
Ticking and knocking
Ticking is often normal expansion of pipes. Loud knocking or banging when faucets close is called water hammer, which can be fixed with arrestors or pressure adjustment.
Screeching or whistling
A high-pitched sound can mean a valve is partially closed or the temperature and pressure relief valve is under stress. That is a safety concern; call for service.
Prevention
Annual flushing and a water softener greatly reduce sediment. If your heater is over 10 years old and noisy, consider water heater replacement or a tankless upgrade.
Quick Answers
Is a noisy water heater dangerous?
Popping alone usually is not, but it reduces efficiency. Screeching or leaks should be checked right away.
How often should I flush my water heater?
Once a year for most Texas homes; more often with very hard water.