case fans running slow

Why Are Case Fans Running Slow On Your PC? [Analyzed!]

Without a good intake and exhaust fan, your PC will get hot and hotter. However, in some scenarios, case fans may start spinning slowly all of a sudden. This of course is not a great sign and should be fixed immediately. 

What are the reasons behind case fans running slow?

The most common reason behind case fans running slow is dirt accumulation. Over time, dirt can gather on case fans and make the blades heavier. Other than that, case fans spinning slowly can be a sign of failure. Case fan speed can also get altered due to buggy software or software clashing. 

Anyway, that was I talking about the possible problems in short. To understand more, you’ll need to learn about the issues in detail.

I’ve also discussed the required solutions in different scenarios. So, hang tight and stay with us till the end to know more. 

Computer Case Fans Running Slow: 3 Reasons & Solutions

Like processors or graphics cards, case fans are equally important in your PC system. Because case fans are vital for ensuring an optimal temperature under the workload.

That’s why most PC users like mesh casings. Because it provides better airflow. If there’s good airflow, you can push your PC further. 
But that strictly depends on casing fans. If the case fans are spinning slowly, you’ll fail to maintain optimal temperature.

Computer Case Fans

This will in turn increase the overall temperature and your system will fail. High temperatures are always bad for PCs. 

A lot of users often compare CPU fans with case fans. This comparison is quite logical but they’re different. They’re also both fundamentally important.

Especially when it comes to airflow, case fans are always the first priority to keep the overall temperature down. 

Some users complain about the case fans running fast. That’s also equally serious because it will drain the fan’s lifespan. 

For case fans running at full speed, you’ll need to check the software. But if the case fans are running slow, you’ll need to take a different approach. 

To keep it simple, we’ve categorized the possible reasons. We then talked about the problem and afterward, we discussed the solutions. 

So, sit back, relax and go through the issues one by one. This way you can easily identify the actual reason and solve the problem. 

Problem 1: Case Fans Accumulate Dirt Over Time & Run Slow

This is the most common reason behind all case fans running at minimum speed. If you feel like case fans have slowed down, this is the most probable reason. 

Since case fans always spin and take air inside, they accumulate dirt slowly. If your PC is on the ground, it’ll accrue even more dirt.

Dirt on Case Fans

Either way, in about 8 months or a year, case fans will be dirty. Dirt doesn’t always affect case fan speeds. But whenever speed is an issue, dirt does play a role. 

The worst thing is that it can even create irritating noise from the PC case-

Some users may question the case fan size instead. Bigger case fans like 140mm case fans usually spin slower than the 120mm fans. 

Bigger or smaller, dirt will be stored on the case fans regardless. This is why cleaning the PC once in a while is a healthy practice. 

Solution: Clean the Case Fans 

To deal with the dirt situation, you have to clean the fans. There are multiple ways to do the process. 

For this, you’ll need a cloth, a brush, and a screwdriver. To do it more efficiently, get a can of compressed air. 

First thing first, get the computer unplugged. Make sure it’s not connected to any electric source whatsoever. 

When you’re done, take the case to an open area. Get yourself masked because there’ll be a lot of dirt to deal with.

cleaning case fan

Start by opening up the case. Inspect the case’s intake fans and the exhaust and where their wires are connected. 

Disconnect the case fan wires from the case fan hub. In PC cases without the fan hub, case fans are connected to different fan headers. 

Now get the screwdriver and start unscrewing the case fans. Get them all out and start the cleaning process. 

Hold the fan’s blade by inserting one of your fingers. This will prevent the fan from spinning. Carefully clean all the blades one by one. 

This is going to take some time. Do it slowly till you’re done. It’ll be way faster should you use compressed air instead. 

Screw the case fans back in and clean the other components. Just use a big brush to get most of the dirt out. 

This is also how you clean the GPU fans. Cleaning the fans is one of many fixes for the RTX 3000 series fan spinning problem

Boot up the computer and the spinning problem should go away.

Problem 2: Failing Case Fans Often Run Slower Than Usual

Dirt isn’t always the main culprit behind case fans running slower. Case fans can fail and show symptoms of failing because they run all the time. 

On top of that, case fans often can be of low quality. Because of that, their lifespan ends faster than other components.

case fans running slower

This can also be an issue when it comes to high-end case fans. After running for a long period of time, any case fans are prone to failing. 

Besides, if you forcefully run case fans at high speed, they’ll fail faster in the long run. 

Solution: Replace the Case Fans 

If the case fans are failing then you’re out of luck. Because there’s no other way to fix the slowing issue. The fans will keep spinning slowly until they die and stop spinning. 

That’s why you’ll have to replace the case fans. Luckily, case fans are dirt cheap nowadays. You can easily find some great case fans under $50 or so. 

Even some of the good medium-range case fans can be found under $30 easily. Look up on different websites and you’ll come across some great case fans. 

It’s best to not cheap out when choosing case fans. Because like we said earlier, case fans are fundamental. You want long-lasting case fans that can keep your PC cool. 

If your PC has multiple intakes and exhausts, you can choose case fan sets instead. The fans that come as a set are usually cheaper than the single pieces. 

There are some great 3-set fans from almost any high-end brand. So it’s best to look out for them as well. 

To help you out, let me introduce you to some of the most beloved case fans-

  • Noctua NF-P12 is one of the most affordable 120mm fans out there. And you’re probably aware of how great Noctua is for PC fans.

You can pick whichever fan you like more and start replacing it!

Problem 3: Case Fans Can Be Set Too Low By Software

Most of the recent medium and high-range PC cases come with a case fan controller. In other words, you can easily control the rotation of the case fans. 

This can also be done by many motherboard software. For example, the Asus Armoury Crate lets you control all the fan speeds. MSI and GIGABYTE also have their own software to control the case fans. 

But software might get buggy if you had a sudden shutdown or a game crash. Sometimes, these bugs stay and can alter the fan speed. 

That’s why you’ll need to check the software whether they’re capping the fan speed. 

For instance, Armoury Crate can make the case fans run faster after the PC boot up. This can be fixed by opening up the software and manually setting the fan speed. 

Solution: Check the Software & Reinstall If Necessary

Fixing and meddling with the software can often fix the speed problem. For that, you’ll need to go to the software that you use to control the fan speeds. 

In some cases, multiple software can clash. One such example is Corsair’s software and Asus’s Armoury Crate. 

That’s why I check all the software for any speed limit. Go to software and look for limits that are in effect. Try changing the fan speed and see if it alters the running speed or not. 

You can try uninstalling the software to see whether it fixes the problem. You can always reinstall the software later. 

For multiple software, you’ll need to do the process a couple of times. But your fans should start running at default speed, once the culprit is uninstalled. 

Check out all the fan-related software one by one. If the software is indeed the issue, you’ll fix it right away. 

Make sure to keep your PC clean all the time. Because cleaning helps you stay out of all sorts of fan problems. 

Frequently Asked Questions (FAQs)

How do I make my case fans spin faster?

You can use motherboard or cooling software to make the fan spin faster. But for that, they’ll have to be connected to a PWM header. Most fan hubs have PWM headers that help you control the speed. Simply set the fan speed to high. And you’ll notice that the fans are spinning faster. 

Can I use WD40 for the case fan?

No, you can’t use WD40 for the computer case fans. Because computer case fans don’t benefit from lubrication. They’re made of plastic which isn’t prone to corrosion and they don’t get stuck. In simple words, computer fans should be replaced for being slow. Lubrication doesn’t help. 

How fast should case fans spin?

The case fans should always spin at a rate between 600 to 1200 RPM. The case fans can reach up to 3000 RPM but it becomes noisy. The fans also lose their lifespan fast. But on idle, case fans spinning at 600 to 1000 RPM is more than enough. During workload, they’ll spin at 1500 RPM or higher.

Take Away

That was everything we could explain on case fan running slow. We hope that this discussion has helped you understand the problems and solve them. 

If you think the above-mentioned solutions are a bother, don’t hesitate to call experts. You can also take your PC to a servicing center and they’ll find the problem!

Finally, have a nice day!

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