What Water Heater Noises Mean

A water heater is arguably one of the most important appliances in your home. It heats water so you can shower, do laundry, and wash dishes.

Unfortunately, they can get pretty noisy sometimes, making you wonder, “Why is my water heater making noise?”

There are several reasons why your water heater could be making noises, and it’s important to find out what they are so you can avoid an emergency call to replace the unit.

Read on to learn what these noises might mean and how you can prevent them from happening.

new water heater installed

Water Heater Noises Defined

There will likely be some background noise from your water heater while it is operating.

The increased demand for hot water in the home during the colder months places a higher strain on your water heater and utility bills.

Some noises are normal, especially with a tankless water heater.

You’ll notice more noise if the water heater is installed in a hall closet than if it’s in the garage.

Many noises coming from your water heater may not be a cause for alarm or intervention.

There are, however, some sounds made by water heaters that should serve as an alarm.

Running Water Sound

If the water heater is making a noise like water running, it might mean you have a leaky pipe or tank. In either case, the first step is to turn off the water to the heater, don’t use hot water, and call a plumber.

We can come out and determine whether there’s a leak or if you have a faulty unit.

There are other sounds that a water heater may make, but whether or not they indicate a problem depends on the kind of noise.

electric water heater element covered in limescale


Sediment accumulation may cause a popping sound coming from a water heater. Minerals in the soil determine how hard or soft the water will be.

A water heater’s sediment buildup is exacerbated by mineral-rich hard water and the lack of routine flushing.

Water is retained when sediment accumulates. This water overheats and builds up pressure because it is surrounded by heat-conducting minerals, causing a popping sound as it pushes through sediment.

The tank’s liner can be harmed by persistently uneven heating and pressure.

Additionally, the sediment buildup can cause lower efficiency, lower water pressure, and less hot water.

Flushing or replacing the unit are two options when you hear this sound.


When pipes that aren’t properly fastened shift, they bang into one another or the wall’s interior.

The noise is known as “water hammering,” and it is triggered whenever there is a sudden shift in water flow when water flows through the pipes.

Although water knocking isn’t immediately dangerous, it can damage pipes or walls if left unchecked.

To quiet the banging, insulate the pipes or fit the valves with a hammer arrestor.

water heater making noises


In most cases, a hissing sound is an indication of a leak. Check the water heater and any pipes that connect to it for any signs of water or steam.

For leaks of this severity, it’s best to call in an expert plumber. A new water heater may be in order if your current one is showing its age.


If you can hear a crackling sound coming from your water heater, this could mean that there’s an electrical problem with it—not good!

You must keep electricity away from your water heater because if they come into contact with each other, they could cause a fire or shock.

If the crackling sound is accompanied by another noise (like splashing), consider turning off your water and electricity before calling us for help.


If your electric water heater makes a buzzing or vibrating noise, water is likely circulating in the heating element.

The sounds you’re hearing might result from vibrations caused by this. In most cases, the issue can be fixed, and the noise can be eliminated by tightening the piece.

flush sediment from water heater


Both bubbling and rumbling are typically brought on by sediment and limescale accumulation in the tank.

The steam bubbles grow under the sediment and explode as the water temperature rises, producing noise.

Use a descaling agent to dissolve the mineral deposits.

However, it may be preferable to drain the tank and start over if there is a lot of silt buildup.

High alkalinity in the tank can also cause an aluminum anode rod to burst. To resolve this problem, a plumber should install a magnesium anode rod instead of the aluminum one.


A banging sound is usually a sign of scale or sediment building up inside the heating element.

When this happens, the water will react with the heating element and create a banging noise that can be heard when you turn on your water heater.

You can resolve this problem by flushing out the tank or installing a new heating element.

If your water heater has been banging for a long time, it may be time to replace it entirely.


The tapping or ticking noises from your water heater likely come from the check valves or heat traps you’ve had to install to ensure the water is flowing in the right direction.

One possible source of this noise is the water’s expansion and contraction as it travels through piping.

You may swap out the trap if you are bothered by the ticking or tapping sound.

The most common reason a water heater makes noise is that it’s old.

As the unit ages, rust and sediment can build up inside, which causes the tank to vibrate against itself when heated.

This causes the rumbling or clicking sound many people hear coming from their water heaters.

If this is happening to you, then replacing your old unit will probably be in your best interest.

If you hear any of these sounds from your closet or basement, call us to get a free estimate on fixing your water heater.

water heater repairs by RT Olson Plumbing Company in Riverside CA

Why is My Water Heater Making Noise?

It’s normal for water heaters to make noise, but a rumbling or hissing sound that doesn’t go away could be a sign of trouble.

If the water heater in your home is making unusual noises and you’re wondering why, it’s time to call us for water heater service.

We’ll come out and assess the water heater for you. If there’s anything wrong with it, we can fix it right away.


There are several reasons why your water heater could make noises, and it’s important to find out what they are so you can avoid making an emergency call to replace the unit.

It’s also critical to learn that not all noises are the same and that depending on the noise your water heater is making, you have to make different adjustments.

Although it’s not unusual that your water heater makes noises, learning what these noises might mean and how you can prevent them from happening in the future is key.

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Owner - Operator at RT Olson Plumbing
Bob Olson has over 18 years experience in all aspects of residential and commercial plumbing. He's a 4th generation plumber. With over 500 five-star customer reviews, he runs one of the best-rated plumbing companies in Corona, CA.
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