Typically, when we see a component with a fan on it, we expect it to be running all the time. This should be the case for most parts, but there are some special exceptions for PSUs that I found during my research.
Some PSU fans come with an ECO mode that will leave your PSU fan off until the load percentage reaches a certain point at which the fan must be on. However, if you don’t have this, you may have a faulty PSU fan.
Let’s take a look at which PSU brands are known for this, how to find out if your PSU has this, and whether or not you should be looking for a replacement PSU.
Why Is My PSU Fan Not Spinning?
As we mentioned, some PSUs have a feature that leaves the fans switched off until they reach a certain usage percentage.
Typically, between 30-50% usage if the fan is not already on, it will get turned on during this usage range.
Once the fans are active, they rely on the fan curve to tell them when to run faster and slower.
If the temperature gets higher, so will the RPM, which is the speed at which your fan will run. Then, when the temperature lowers, so will your RPM.
To get to this usage, you will probably have to play a game or do some other intensive activity that would put more stress on your PSU.
Then, once you reach your PSU’s threshold for usage during your gaming, the fan will turn on to cool the PSU.
If you are simply browsing the web or doing some other low-intensive task, you probably won’t reach the usage needed, so the fans will not turn it on.
This is found on several higher-end PSUs, and people usually search for this if they want a super quiet PSU that runs its fans to the minimum required.
Before you commit to loading up an intensive game to try it out, you should check to make sure this is a feature your PSU has and that it isn’t something wrong with your PSU.
A great way to see if this is the case for your PSU fan is to go to the sales page on the official website of PSU’s brand.
For example, if your GPU was the EVGA SuperNOVA, you should look up that product and go to the EVGA website.
Here you can see the full feature breakdown, and if your PSU has this, it is usually listed somewhere because PSU companies are proud of this feature.
Corsair is another brand that is known to have this feature on their higher-end PSUs.
If you don’t have this feature on your PSU and your PSU fans aren’t running, this may be a sign that your PSU fans are faulty.
In this case, you should seek a replacement from the manufacturer or a refund so you can buy a new PSU.
There are ways to replace the PSU fan. However, I wouldn’t recommend it if you aren’t familiar with PSUs’ construct or are a novice PC builder.
It can also be very dangerous to crack open and modify due to a PSU’s nature and the electricity that runs through it.
The fan needs to have the functionality to turn on because there is no other way for your PSU to get cool without it.
This can lead to your PSU overheating and your PC being forced to shut down. In the worst-case scenario, you may even damage some of the parts in your build.
So if your fan isn’t spinning and it’s not because of an ECO mode or zero-noise feature, you should probably seek out a replacement as the safest path to fix this issue.
How To Monitor PSU Temps?
Unfortunately, most PSUs don’t have a temperature sensor, so getting exact temperature readings will be out of the question for most.
One premium Corsair PSU called the AX1600i has a temperature sensor built in to monitor performance.
The AX series is the only series from Corsair with a temperature sensor that I could find in my research.
Other than that, you really have to go off of feel and the shutting down of your PC.
A sure sign that your PC is getting too hot is to experience shutdowns since that is an emergency procedure to prevent further damage.
If you want to avoid that beforehand, you can put your hand near the side of your case where the PSU.
If you feel lots of hot air coming from where your PSU is located, and it feels irregular, this could mean your PSU is getting too hot.
However, unfortunately, the only way for most people to know this for sure is if your PC shuts down.
Why Is My PSU So Hot?
If your PSU is running very hot, this could be the result of the fans not working. Since the dedicated cooling solution isn’t functioning, your PSU will overheat as a result.
If you haven’t experienced a forced shutdown yet, you could soon because that is the failsafe to prevent disastrous side effects of the PSU overheating for too long.
Take a look at your PSU fans next time your computer is on and see if they are running.
Another thing that makes people’s PSUs run too hot is placing your PC on a carpeted floor where the air cannot flow out of the computer properly.
You should elevate your PC and make sure there is ample room for the air underneath to escape from your PSU.
By blocking this off, you cut off the airflow, and it stops the PSU from being able to disperse the hot air and bring in new cold air.
You should have your PC on a desk or on some kind of hard, flat surface with clearance underneath for air to pass through.
Also, make sure the PSU fan is facing downwards towards the outside of the case.
The inside of your PC will be much hotter than the outside, and the fan on a PSU is actually an intake fan.
This means it will use the fan to pull the air in from the direction it is facing.
So ideally, you want the intake fan on your PSU to face the bottom of your case where it can pull in the cold air from your room.
Finally, check the bottom of your case where your intake fan is facing for an intake filter.
Some cases have a dust filter at the bottom of the case to prevent the dust from getting pulled in by the fans.
I have a dust filter on my Fractal case, which I have to clean routinely.
If this fan is clogged or covered in dust, it can impact your PSU’s airflow and prevent it from being able to cool.
This can also cause overheating because the hot air will get trapped with the PSU leading to that very hot feeling when you touch it.
First, check to ensure that you don’t have a PSU with some fancy features such as low noise or ECO mode.
Features like those found on some EVGA and Corsair PSUs will turn off your PSU fan in low-load situations where cooling isn’t needed.
If you discover that you don’t have this feature, returning your PSU is likely the best option, especially if you experience overheating your PSU while using your computer.
You will notice this primarily while playing games or putting your PSU under heavy load, but not much on your desktop.
There are ways to change out the fans, and there are even guides online for this. However, from my research, it seems like an option that isn’t very safe.
If you have a faulty PSU with non-functioning fans, that should be eligible for a return or replacement.