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Why Do Electric Heaters Make Noise? 5 Common Reasons

Virtually all electric heaters make some sort of sound. Crackling, popping, humming, and buzzing are all very common. But why do electric heaters make noise?

If your electric heater is making noise, here are a few possible causes:

  1. The heater makes a popping sound when it expands.
  2. The fan is making noise.
  3. The electric coil heater is vibrating.
  4. The screws holding the heater together are loose.
  5. The mounting brackets aren’t installed correctly.

In this article, I’ll explain some common reasons why electric heaters make noise. I’ll also explain why electric wall heaters and electric baseboard heaters make noise.

1. Popping Sounds Happen When the Electric Heater Expands

This is the most common reason why your electric heater makes noise. It’s more noticeable in larger types like electric baseboard heaters.

The clicking, banging, popping, or however you want to describe it happens because the molecules expand when they’re heated.

Heated molecules are faster, so they increase in volume. And heat energy becomes kinetic energy, so that’s where the noise comes from. You can’t see this, but you can surely hear it. It’s also unavoidable, but it’s not a cause for concern.

You can typically notice this only when you first turn on your electric heater. If it runs on a thermostat, it happens whenever it switches on.

The popping and clicking also happen when you turn the heater off. The materials cool down, which causes them to lose energy and shrink.

There’s no way to fix this type of noise, though. Larger electric heaters made of thin metal will cause a lot of banging.

The only workaround is to adjust your thermostat. If you can control when the heater is on, you’ll know when it’s going to pop and bang.

Additionally, don’t leave your heaters on overnight if possible. Or get a smaller room heater for the evenings. They’ll also bang and pop, but it’ll be less audible.

2. Fans in Electric Heaters Make Noise

Many types of electric heaters use fans to blow warm air into the room. It’s generally more efficient than radiating heat, and it’s especially useful if the electric heater is small and portable.

But fans can get very loud, especially if they’re low quality. The fan bearings can cause noise from friction.

Here are a few common causes of fan noise in electric heaters:

  • There’s dust on the fan blades or in the fan bearings.
  • The fan bearings are old and worn out.
  • The fan bearings are rusty.
  • The lubrication in the fan bearing has dried up.

Fixing a noisy fan in an electric heater isn’t a big deal; you can even have it replaced. The biggest challenge is finding the right replacement fan.

I don’t recommend opening up your electric heater unless you’re an electrical technician. If you do have the technical know-how, then you could do it.

Here are the steps you should take to fix a noisy electric heater fan:

  1. Open up the electric heater.
  2. Unscrew the fan and remove it.
  3. Clean any visible dust on the fan blades.
  4. Remove the fan blades to find the fan bearings.
  5. Thoroughly clean and lubricate the fan bearings.
  6. Put the fan back in, and reassemble the electric heater.

Note that you can’t use just any type of lubricant on fan bearings. Those are delicate parts that you can’t fix with some WD-40 and machine oil.

Instead, use the Liquid Bearings Synthetic Lubricant (available on It’s a special lubricant made for fans. It comes with ½ in (1.27 cm) and 1½ in (3.81 cm) needles so that you can apply only as much oil as you need.

3. Old Electric Coil Heater Is Vibrating

Electric heaters use coils to convert electric energy into thermal energy. It’s a simple yet genius design that has kept our homes warm for decades.

But heating thin coils to extreme temperatures creates some undesired side effects. Remember that thermal energy becomes kinetic energy when it’s heated up?

That’s what happens to the coil inside your electric heater. Except that this time, the temperature is so extreme that the coil starts vibrating.

To counteract this, manufacturers varnish their coils. It significantly prolongs the coil’s lifespan and improves resistance to environmental stress.

But the varnish wears off over time. If your electric heater is old, then the coil will vibrate.

The vibrations cause an irritating buzzing sound, which is especially noticeable at night.

Replacing a coil isn’t impossible, but it can get very expensive, so you’ll probably be better off buying a brand-new electric heater.

A Redditor even recommended kicking the heater, but I strongly advise against that.

4. The Screws Holding the Electric Heater Are Loose

Screws get loose over time. If there are visible screws on the electric heater’s housing, tighten them.

But the bigger problem is the screws holding the mounting brackets. If you have a wall-mounted heater, that is.

Loose screws can cause the electric heater to vibrate. The noise is further amplified if your electric heater uses fans.

So, tighten all the bolts and screws holding your electric heater. But don’t tighten them too much because that won’t leave any space for expansion.

5. The Mounting Brackets Aren’t Installed Correctly

Related to the previous point, improperly installed mounting brackets can cause noise from vibrations.

The electric heater could even fall off the wall if the brackets are too loose.

You should check the user manual to see if you mounted the brackets correctly–perhaps the brackets aren’t level, or you switched the left and right bracket.

If everything looks alright, tighten the brackets just to be safe.

Why Electric Water Heaters Make Noise

Electric Water Heater Has Trapped Air Bubbles

Let’s now shift our focus toward electric water heaters. They have a slew of unique problems, including trapped air bubbles, which cause gurgling noises. But a bit of air is completely normal and inevitable.

There has to be enough space for the water to expand, so you can’t do too much about it. However, this expansion affects the air bubbles, too.

The gurgling and popping sound concerning, but thankfully, it’s nothing dangerous. 

Watch this YouTube video explaining how to “burp” your water heater:

Note that this isn’t a problem with oil-filled radiators. Oil-filled radiators are full, so there’s no air to cause unwanted noise.

Electric Water Heater Is Full of Sludge and Lime

Dirty water is a major issue if you use a hot-water radiator system to keep your home warm in winter. 

Your electric water heater is significantly less efficient if the water isn’t crystal-clear. So, if you’ve noticed that your electricity bills have gone up over the past few years, this might be a reason.

Sludge also causes a lot of noise in the heater, pipes, and radiators. Sediment causes gurgling noise when cold water goes to the bottom of the tank.

But where does all that nasty sludge come from?

The water in your heater is full of limescale, which builds up over time. Also, your heater and radiators rust slightly over time. And there can even be bacteria multiplying in the warm water.

To solve the issue, you can dump some Rectorseal Water Heater Flush (available on into your electric water heater. This product is biodegradable and a fast-acting agent that will clean your tank, radiators, and coils of any limescale buildup.

Electric Wall Heater Making Noise

There are several reasons why an electric wall heater makes noise. When you first turn the electric wall heater on, it’ll cause some noise.

However, this initial popping is a normal part of the warmup process. The molecules move faster, which causes expansion of your wall heater and the wall it’s attached to.

But after a few minutes, the heater shouldn’t be making any noise. That’s aside from the slight hum from the coils and fan (assuming your heater uses one).

If the wall heater is very noisy, it’s because it wasn’t mounted correctly. 

Buzzing sounds can happen when the mounting brackets are loose, but you can fix this by tightening all the bolts and screws you see.

Eco Home explains that you shouldn’t tighten the brackets too much, though. The metal will slightly expand when it heats up. 

So, only tighten them enough that they don’t move when you touch them.

Additionally, the electric wall heater makes noise if there’s wall decor underneath it. Or perhaps the wall surface is uneven, as noise is common on textured walls.

To fix this issue, you’ll have to remove the electric wall heater. But you’ll have to get your paint roller ready because you’ll have to make the wall smooth.

Watch this YouTube video on how to do skim coating for beginners:

Once your wall is flat and dry, mount the wall heater. If there’s still noise coming out of it, it’s most likely an old electric coil.

Electric Baseboard Heater Making Loud Banging Noise

Electric baseboard heaters don’t have fans, so they shouldn’t be noisy, right?

Surprisingly, these heaters can be very loud. The banging can get so loud that it might wake you up at night. But what causes them?

Once again, the most common reason is thermal expansion. Baseboard heaters create radiation heat, which slowly warms up everything around the heater, including the heater itself.

The thin metal housing expands when heated, which causes it to bend and cause loud banging noises. And it shrinks as it cools down, which has a similar effect.

Your thermostat turns the baseboard heater on and off multiple times in an hour, which causes a lot of banging and popping.

Unfortunately, there’s not much you can do about this. However, you could try adjusting your thermostat to make the heater turn on or off less often.

Also, a larger baseboard heater means more surface area. So, a smaller model will be less noisy.

Another solution would be to use a baseboard heater with a separate thermostat. At the very least, you’ll know when the heater is on. You won’t be startled by the banging.

Hydronic Baseboard Heater

In addition to the inevitable noise from expansion, hydronic baseboard heaters have another issue.

Excessive air pressure in the baseboard heater can cause banging noises, but you can refer to your baseboard manual to see how to access the pressure release valve.

It’s something that you can do yourself. But make sure that the heater is off before you do this because opening a release valve when the heater is still hot is a recipe for disaster.

Final Thoughts

Electric heaters are noisy devices that keep our homes cozy; an occasional pop or bang is normal. All heaters suffer from thermal expansion that makes molecules move faster and create noise.

However, if there’s an audible hum, its coil is getting old. Changing the heating coil is difficult and expensive, so it’s best to buy a brand-new heater.

Wall and baseboard heaters can also suffer from loose screws and bolts, causing slight vibrations and noise. Tighten everything to prevent this.

Flushing the system and releasing the air is an easy fix to trapped air or dirty water can make unwanted noise.


  • Jake Alexander

    Jake is a freelance writer from Pennsylvania who enjoys writing about science and sports. When he's not writing for Temperature Master, he can be found watching the NFL or playing basketball with his friends.

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