What To Do When Your Water Heater Is Making Noises

Why is My Water Heater Is Making Noises

When working correctly, your water heater is supposed to be relatively silent. So, when it suddenly starts making noise, it is usually a sign of some underlying technical issue.

One of the easiest ways to identify the water heater’s issue is by recognizing the type of noise it makes, as each part will make a different sound when it malfunctions.

We will explain what noises water heaters usually make, what kind of issue they are signalling, and what you should do when you hear each of them.

What To Do When You Have a Water Heater Making Noise?

A water heater doesn’t make noise for no reason. And while some noises are associated with much bigger issues than others, every unusual noise is connected to some malfunction. It should be treated as a warning to turn off your heater and call a professional plumber to check on it.

Here is a list of the most common water heater noises and problems then you should look for when you hear them

9 Common Water Heater Noises and What They Mean

Some of the noises on this list may result from several different problems, or a single malfunction can create other noises based on whether you are using an electric or a gas water heater, as well as the heater’s model and age.

Furthermore, tankless water heaters are exempt from some issues, as they are strictly related to the holding tank.

Still, there is a clear connection between specific noises and the underlying causes in both gas and electric water heaters, which we will now explore.

1. Humming noises

If your water heater makes a humming noise while switched on and active, it is usually a sign of loose pipe straps or other components. Loose parts can be dangerous if the water starts to leak and comes in contact with the power cords, so you should fix the issue as soon as you notice it.

Thankfully, silencing this humming sound is simple. Switch and plug off your water heater, cut it off from any water flows, and leave it until the water inside cools down to avoid burns by heated water. Finally, tighten any loose parts back in place to eliminate the humming sounds permanently.

2. Knocking or Hammering Noise

This is another common water heater noise, one that can be a result of several different issues.

Firstly, it can be caused by the pressure in your pipes, as the water heater cannot handle shutoff valves being closed too quickly.

This is the lesser of the two problems and can be solved simply by installing a water hammer arrestor. It will stop the water hammering into the valve and silence the noise.

The second and much more significant issue is when your water heater collects too much sediment.

Such sediment build up takes time, but the results can be pretty problematic when it happens. The sediment will move up and down the water heater, causing noise as it stops the steam bubbles from reaching the water’s surface. Furthermore, it will also reduce water quality.

In this case, the best thing to do is call the plumber to clean the mineral deposits from the water heater tank.

You can also put a filter between the pipes and the water heater to prevent excess sediment buildup in the future.

3. Screeching Sounds

Screeching sounds usually signify a problem with the inlet control valve and are not a cause for much concern. Simply adjusting the valve so it fully opens will resolve the issue.

If the noise persists, the next step is to call a plumber, as he will have the tools needed to open the valve if the usual means fail.

4. Ticking Sounds

If you hear a ticking sound from your water heater, there is no genuine issue to be worried about. As the hot water in the water tank comes in contact with the cold water coming from the pipes, it causes a change in the water pressure, causing the pipes to make noise as they adjust to it.

You can eliminate this noise by reducing the temperature of your water heater and adjusting the pressure relief valve.

5. Crackling Sounds

A crackling sound can often be heard due to excess condensation on the water heater burner. This is especially common in gas burners and is not a cause for concern.

While the sound may be annoying, these water droplets will disappear rather quickly as the water heats, taking the crackling noises with them.

6. Tapping Sounds

A tapping sound coming from your water heater is most often caused by heat traps, which aim to control the water flow by allowing only cold water to enter the heater.

This tapping noise is entirely normal and is rarely a cause for concern, as it comes and goes as the heat trap controls the water pressure balance between the water tank and the pipes.

7. Sizzling Sounds

Sizzling sounds are a significant cause for concern when coming from the water heater. If you hear your water heater making noises like these, the hot water tank is leaking.
A leaking water heater isn’t just annoying to deal with; it can also be hazardous, causing burns or even a fire in case the water comes in contact with the electric installations.

Call your plumber immediately and schedule service if you notice a leaky water heater or a puddle of water on the floor. Depending on the issue, you may need new pipes, a new holding tank, or even be forced to get a new water heater entirely.

8. Rumbling Sounds

Rumbling sounds are usually a result of the heating element of your water heater making the water too hot. The easiest way to resolve the issue and silence this rumbling sound is by getting the water flowing again by using some of it.

This will allow the running water from the pipes to enter the water heater, lowering the temperature inside it.

9. Popping Sounds

If you hear your water heater making a noise that resembles popping, it is usually the result of mineral deposits accumulating within the hot water tank. The best way to resolve this issue is to flush your water heater, letting a fresh water supply enter the tank and remove the sediment buildup.

Frequently Asked Questions

Why is my water heater making noises?

A water heater making noise is most likely malfunctioning in some way. It is possible to identify the exact problem by determining the type of noise coming from it, which will then tell you what needs to be done to fix the issue.

How do you stop a hot water heater from making noise?

Depending on the type of noise it makes, there are several different things that you can attempt. If an overheated heating element is causing noise, you should let some cool water into the tank. If you are having a problem with sediment build-up, flushing the water heater will do the trick, etc.

What does a bad water heater sound like?

The most alarming noises coming from a water heater are the sizzling ones, which usually indicate a leaking tank. Such a malfunction is especially dangerous in the case of an electric water heater, as the leak can come in contact with the cables, setting your home on fire. If you ever notice a leaking tank, switch off the electricity and call your plumber immediately.


If you hear your water heater making noise, it is likely experiencing some technical issue. Most of the problems are benign and don’t require your immediate attention.

However, knowing which kind of noise you are hearing will allow you to pre-emptively resolve any issues and schedule water heater repair if necessary.

Smith Edwards

Smith Edwards is a licensed plumber and writer with over a decade of hands-on construction and home improvement experience and has been providing home improvement advice for over 12 years.

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