Power Inverter Making Noise? Here’s Why and How to Fix It

By:Michael Johns

Is your power inverter making a noise that’s worrying or annoying?

It’s happened to me before too.

The biggest piece of advice I can give you is to not ignore your power inverter making noise.

As the old saying goes, you can’t run from your problems.

In the long term, an inverter that’s making a strange noise is going to cause more problems and even be a safety risk.

If you want to know what the noise means and how to fix it, then keep reading.

In this article, I’ll go through all the most common problems and what they sound like. This should help you identify your issue and work out what to do.

Let’s get stuck in, you can easily use the table of content to quickly find what you’re looking for 👇 

Common Power Inverter Noises

Here are some common noises an inverter makes that could mean you have a problem.

Overheating – Fans Really Loud

Can you barely hear yourself think over the sound of your fans?

While your fans will make some noise every so often, they certainly shouldn’t be running at full speed all of the time creating a lot of noise. It’s not very nice to live with the constant whooshing sound!

If this is what you are experiencing then it is a clear sign that your inverter is overheating. Your fans and cooling system are working overtime to try and dissipate heat.

There could be a few reasons for this, firstly you should check how much load and wattage you are drawing. If you are constantly reaching the maximum or even 80% then you are putting a lot of strain on your inverter. You should try to reduce the amount of power you are drawing. 

You don’t want to run an inverter on max load all the time. It’s a bit like driving a car, you don’t (or shouldn’t) drive everywhere with the gas pedal fully pushed to the floor. You’ll burn a lot of gas and reduce the lifespan of your engine.

If the amount of load you are drawing isn’t excessive you should also ensure you’re inverter is placed in a well-ventilated area. You should allow the fans to draw cool air expel hot air. So don’t place cooling fans against a wall or soft furnishing, plus don’t use them in an enclosed space.

Fan Obstruction – Clapping or Rubbing

Another really common reason a power inverter makes noise is due to a fan obstruction. This can sound like a clapping or a rubbing sound.

Generally, this is pretty simple to fix. You just need to remove the debris that is in the way of the fan. The sound comes from the spinning fan blades hitting an object. This means it will sound like something continually clapping, rubbing, or flicking.

If the debris comes from something outside of the inverter then there’s no need to do anything else but remove it. Should the debris look like an internal component then it will mean further investigation to find any internal damage or components that have come loose.

Low Wattage or Low Voltage – Squealing 

One thing you might not realize is that when you have low battery your inverter will make a squealing noise. This is due to a low voltage being supplied to the unit. 

If you hear a squeal or high-pitched scream then check your energy supplies. A low battery can be checked on an inverter via the digital display. Some inverters will be able to give a direct battery charge reading. Plus if your voltage level drops to 10 or below this is a sign of low power.

Fortunately, lots of modern devices have a low voltage auto shut-off to help avoid this problem.

Of course, this has an easy fix – charge your battery!

Wrong Cable Size – Squealing

When your inverter has plenty of energy in your battery but is still making a squealing sound this can mean there is a problem with the cables.

Firstly, this is usually down to having the wrong cable size. This is due to the wire thickness which is referred to as AWG. Different size inverters need different size AWG cables. For example, you can get 6 AWG ables, 4 AWG cables, and 2 AWG cables. The larger the AWG number the smaller the physical wire size is!

To give you an understanding of what you might need here’s a chart for wire size and inverter size:

AWG Cable SizeInverter Size
11000 Watts
4500 – 1000 Watts
8250 – 500 Watts
10Less than 250 Watts

The numbers above are guide and not a set rule as cable size will also depend on the length of cable. If in doubt, use a thicker cable.

If your cables are suitable for your inverter (if they arrive with the inverter they should be fine) then check the connection to make sure this is clean and tight. Loose/poorly connected wires will make a similar sound.

Overload – Beeping

Most modern inverters include an audible alarm which will sound when there is a problem. 

You should check your user manual as this should tell you what different alarms mean. Usually, this is the number of beeps the inverter makes at a time. 

The most common reason for an alarm to sound is due to overloading. That means you’re trying to draw too much power than your inverter can handle. The beeping sound means you risk drawing too much power. You should reduce the load before the inverter damages itself and starts to overheat. 

Most inverters have a surge protection and will shut down automatically when it becomes overloaded. To reset an inverter overload you should switch off the power and unplug your appliances. Leave the inverter to cool down for a few minutes, then turn it back on with nothing connected to check it’s working correctly.

Faulty or Damaged – Clapping, Grinding, Hissing, or Clicking

If you have any other strange sounds coming from your inverter such as grinding, hissing, or clicking then you can’t find a reason for then there could be a more serious fault.

Can you hear a rubbing, clapping, or grinding noise? Then it is likely that there is a problem with the internal components. When not in use, give the inverter a little shake to see if you can hear anything rattling around. Try to identify any loose parts that could be creating this noise.

Should this be a problem, the internals of the inverter will need to be repaired. This will require unscrewing the housing and opening it up to find the problem. If you are not confident in this then find a professional to help.

Modified Sine Wave – Buzzing Sound

One final thing I want to bring to your attention is a buzzing sound. This only really applies if you have a modified sine wave inverter.

Modified sine wave inverters are cheaper and step up and down the voltage rather than creating a smooth wave. This leads to higher harmonic distortion and a buzzing sound. The abrupt ‘square wave’ created by the magnetic field leads to vibration in the metal which causes a ringing. Plus the higher harmonic distortion creates interference with speakers, radios, and TVs.

There is nothing you can do about this sound and it is not a fault or problem. It’s just the way modified sine wave operates. If you find it too annoying you should get a pure sine wave inverter.

Final Thoughts on Inverter Making Noise

I hope you’ve been able to find the reason your inverter makes a noise.

While the reasons above are not an exhaustive list, they are the most common problems.

Many of them are quite easy to fix whether it’s the wrong cable size or a fan obstruction. If you think the problem is more serious then you should immediately fix or replace your inverter.

A fault inverter presents a fire risk to you, plus can damage your appliances and electronics. Either way, it’s not good.

Thinking about a new inverter? Then read our guide to the absolute best power inverters.