Water Heater Making Noise? What Popping, Rumbling and Hissing Mean
By JW Moore Plumbing • Updated 2026-09-17
Different noises point to different problems — and some mean your tank is near the end of its life.
Popping or rumbling
Sediment on the bottom of the tank traps water that boils and pops. Flushing helps early on; heavy buildup shortens tank life and drives up energy use.
Hissing or sizzling
Water dripping onto the burner or a leak from the tank itself. Check for moisture under the unit — a leaking tank needs replacement.
Ticking or knocking
Usually pipes expanding and contracting. Pipe straps and a heat trap solve it.
Screeching
A partially closed inlet valve or a bad element on electric units.
Repair or replace?
Tanks older than 10 years with sediment noise and rusty water are candidates for replacement, and a tankless upgrade may pay for itself.
Need a Plumber Now?
JW Moore Plumbing offers water heater repair across Hawaii — 24/7, same day, flat-rate pricing. Call (888) 480-9811 or book online.