Water Heater Making Noises? Plumbing Pros Weigh In

When you walk past your water heater, you may hear it making strange sounds. The sounds could be pops, bangs, whistles, or even hisses. Some of those sounds can be annoying or even downright scary. Before you start running back upstairs for fear of your water heater being haunted, rest assured it’s quite common for water heaters to make noises.

The question is why is it making those noises and what do those noises mean? Now that we’ve discounted the haunting theory, let’s take a look at the noises, what causes them, and what you should do about them.

Is It Normal for a Water Heater to Make Noise?

Sure it’s normal. A water heater is a mechanical device that heats cold water so the water is ready to use for your shower, washing machine, or dishwasher. Just like any other mechanical device, the water heater makes noise.

However, that doesn’t mean that the noises should be ignored. If you listen closely, you can identify the type of noise it’s making and get an idea of what the noise means and whether it is a sign that your water heater needs service.

What Are Common Water Heater Noises and What Causes Them?

There are a variety of noises that you might hear coming from your water heater. Here are the most common ones and their possible causes. In all cases, you could try simple solutions for the problem, but it’s always best to call in a professional.


A water heater making popping noise is due to sediment buildup. Sediment buildup is a normal occurrence in hot water heaters, especially if you live in an area with hard water. Steam bubbles can form under the sediment and then burst through as the water heats up. The bubbles bursting through the sediment create the popping sound. You could try a descaling product to fight the sediment. You can also try flushing and draining the tank to remove the sediment.


Also known as water hammer, banging is caused by pressure in the system when the water stops or changes direction forcefully. Water hammer is strong enough to burst pipes, so calling a professional may be the best course of action.


Water heater whistling or high pitched sounds are usually caused by water under pressure that’s being forced through a small opening. It could be because a valve is not fully opened. Listen carefully to determine the location of the whistle because whatever valve is whistling may need to be replaced. If the valve is close to the water heater, leave the valve changing to a professional since there is a risk of steam burns.


A water heater making hissing noise is usually associated with electric water heaters. The hissing sound is caused by the lower heating elements being covered by sediment. Flushing and draining the water heater can help with this problem.


A water heater making humming noise is probably caused by a loose heating element. The loose element makes the water around it vibrate, creating a humming sound. Tightening the element should eliminate the hum.

Like Water Running

A water heater making noise like water running could simply be the water entering the tank. However, If the sound continues, it could indicate a leak or a broken pipe.

Like Vibrating

A water heater making vibrating noise or rumbling noise is most likely caused by sediment buildup in the bottom of the tank. Boiling water gets trapped under the sediment and the bubbling causes the vibration.

What Should I Do When My Water Heater Is Making Noises?

If you hear your water heater making any of the above noises, it’s important to take action. If you’re handy and know something about plumbing, you might try a do-it-yourself fix. However, when dealing with plumbing and the hot water and steam involved with water heaters, it’s best to leave things to the professionals.

What you definitely don’t want to do is take matters into your own hands, especially if you have no plumbing experience. The result could be water damage to your house and injury to yourself.

Water heaters are an important part of your home and you want to make sure they are operating in peak condition. Any strange noises you hear could be a sign of greater problems. Let Nick’s Plumbing help you with all of your water heater inspections and repairs. Contact us today to schedule an appointment.

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