A water heater usually makes unusual noises because sediment has built up in the bottom of the tank, water hammer is shaking the pipes, mineral scale is coating an electric element, pressure inside the system is too high, or the relief valve is releasing water. Each sound has its own likely cause.
A Quick Sound Guide
- Popping or rumbling: sediment at the bottom of the tank
- Crackling or sizzling: scale on an electric element, or condensation dripping onto a gas burner
- Banging when a tap shuts off: water hammer in the pipes
- High-pitched whine or screech: a partly closed valve restricting flow
- Hissing near the top: the relief valve or a leaking fitting
Sediment Is the Most Common
Minerals in the water settle in the tank over time. When the bottom heats up, water trapped under that layer turns to steam and pops. Sediment also makes the heater work harder and can shorten its life. Flushing the tank can help if the buildup has not hardened.
Pipe and Pressure Noises
A loud bang when a faucet or washing machine valve closes quickly is water hammer. It can loosen joints over time and may point to high household water pressure. A plumber can test the pressure and suggest fixes like a pressure reducing valve or hammer arrestors.
When a Sound Is a Warning
Hissing with steam from the relief valve pipe, banging that keeps getting louder, or any noise that comes with a leak or a burning smell should be checked right away. Turn the heater off and keep people away until then.
If your heater is making new noises, a plumber can drain the sediment or replace worn parts. Scheduling an annual tank flush can help keep sediment under control and the heater running quietly. Ask about it at your next visit. Call JPR Plumbing at (833) 603-1840.