Water heater noise is common and can be annoying if its installed
in or near your living space.
Noisy water heaters are described as humming, singing, screaming
rumpling, crackling, popping, ticking, tapping, hissing, sizzling,
knocking, pounding, and hammering.
Some unusual descriptions I’ve heard are – sounds like a cat screaming,
finger nails on tin, chair dragging across the floor, bacon frying and
some I can’t repeat.
If water heater noise is keeping you up at night, or has you worried,
read on to see what steps to take.
An electric water heater noise you may hear is humming.The heating
element has a looped tube. If the space between the tube is vertical
to the tank it may cause a humming noise.
This sometime occurs after the elements have been replaced and
on a new water heater.
It will not cause damage to the element or the tank. However, if you
want to stop the humming, tighten the element one eighth to one
Gas water heater rumbling is caused by excess sediment in the tank.
Calcium or lime deposits, rust, and other debris build up over time.
Water becomes trapped under these deposits and makes a popping
or cracking sound when its heated. As the amount of sediment builds
up in the tank you will began to hear a rumbling sound. As the amount
of sediment builds so does the noise increase.
Rumbling is normal in a water heater that has not been flushed or
cleaned on a regular basis. It will not blow up. It is annoying if it
is located inside your home.
To solve this problem the tank needs to be flushed and cleaned or
treated with a deliming solution.
Electric water heater elements will make a cracking, sizzling, popping
hissing or sizzling sound when they become covered with sediment.
An element can be removed and cleaned with a wire brush or vinegar
if the noise is disturbing. May reduce element life over time but
will not cause any other problems.
Most water heaters have steel tanks. Steel expands and contracts
when its heated or cooled. This can cause popping or cracking.
Plumbing pipe can be also expand and contracts creating noise.
This happens when water under pressure is forced through or
around an object.
Most common problem is a shut off valve not open fully. This
could be the shut off valve at the water heater or under a sink.
Open valve completely.
Heat traps can cause a ticking or tapping sound. Heat traps are
built into the nipples on top of the water heater where the plumbing
connects to the tank.
The ticking is normal. Heat traps are not necessary. Remove and
replace with standard die-electric nipples.
Plumbing can also have a ticking or tapping sound when its cooling
off. This is also normal.
Water Hammer – Knocking/Pounding
If it sounds like someone is beating on your wall with a hammer, you
have what is called “water hammer”.
Water hammer is not a water heater noise. It is caused by water rushing
through the pipes and being shut off quickly. The water stops abruptly
and tries to push back up the pipe. This causes the pipe to bang the
Water hammer should be fixed as soon as possible. Its not likely to damage
the walls but will burst the pipe and cause a flood.
The most common causes are dishwashers and washing machines with
automatic valves that shut the water off fast. Shutting any faucet off fast
can cause water hammer. Toilet valves can cause water hammer.
Determine where the problem is and install a “Water Hammer Arrestor”
between the appliance or faucet and the water pipe.
Water hammer arrestors can be had specifically for washing machines,
under sinks or to fit any size water pipe.