Cleaning thermal paste off a CPU is something every PC builder eventually has to do. Whether installing a new CPU cooler, refreshing old thermal paste, or even upgrading to a new processor, it’s handy knowledge that’ll save you from making a mess. So, without further ado, let’s show you how to clean thermal paste off a CPU quickly and easily.
What You’ll Need
Cleaning thermal paste (sometimes known as thermal interface material) is simple as long as you have the right tools. To do the best job, you’ll need:
- Lint-free paper towels (these XFasten Kitchen Towels do a great job)
- High-purity isopropyl alcohol (90% or above)
You may be able to get away without the isopropyl alcohol (IPA) if your thermal paste is still fresh. However, we recommend using the IPA anyway, just to be safe. It’s affordable and ensures both surfaces are as clean as possible.
We advise using at least 90% IPA when you remove thermal paste because it’ll dry quickly without leaving any residue or liquid behind. Rubbing alcohol contains other substances, such as water and perfume oils, which won’t evaporate as cleanly as isopropyl alcohol. They will stay on your CPU and cooler even after the IPA evaporates.
While that will rarely be dangerous, we don’t think there’s any reason to use rubbing alcohol when you can get 99% IPA for less than $8 on Amazon. You won’t need much, either, so the 16 fl oz bottle we linked above will last a long while.
How to Remove Thermal Paste
Now that you have everything, it’s time to start.
1. Remove Your CPU Cooler
First, you’ll want to remove your CPU cooler. The process will differ depending on the cooler you currently have installed on your CPU, but the basic process is the same for almost all CPU coolers. First, unplug the CPU cooler fan from the motherboard fan header. Then, you’ll need to unscrew or unclip the cooler from the mounting hardware. Once that’s done, it’s time to lift the cooler off your CPU.
Note that you should be extra careful when removing the cooler if you’re using an AMD Zen 1, Zen 2, or Zen 3 CPU. The mechanism that holds the CPU down is very weak, and you could pull the CPU out along with the cooler if you’re not careful.
This can lead to bent CPU pins, a headache to fix. So, don’t pull the cooler out vertically; instead, gently twist it so it comes away cleanly.
After removing your CPU cooler, you’ll notice a gray gunk sticking to your CPU and CPU cooler. This is the old thermal paste that you want to get rid of. Dip a paper towel in some isopropyl alcohol (IPA) and wipe the bottom of your CPU cooler until it’s clean.
2. Clean Your CPU
Most of your old paste will likely be on your CPU. Use another IPA-soaked paper towel and wipe the paste off your CPU. It may take a few goes, so keep wiping until you get a clean heat spreader with no remaining thermal paste. You may notice some tarnishing on the CPU after removing thermal paste; that’s normal and nothing to worry about.
Ensure you don’t leave any stray fibers on your CPU or motherboard, especially not in the CPU socket. So don’t use a paper towel until it tatters and falls apart. Instead, change towels with each wipe when you remove thermal paste.
Once your CPU is clean, wait until it’s dry before proceeding. If you’ve used high-purity (≥90%) IPA, that should only take seconds.
3. Apply New Thermal Paste and Reinstall Cooler
Whether you’re swapping coolers or building a new PC, you’ll need to reapply thermal paste to your CPU before you can get your system up and running. If you’re installing a new CPU cooler, you likely received a tube or packet of thermal pa ste with it. If not, you can buy aftermarket thermal paste such as Arctic MX-6, Noctua NT-H1, or Thermal Grizzly Kryonaut.
Some coolers, including stock coolers and many AIOs, will have thermal paste pre-applied. If so, you can skip this step and install the cooler directly.
PC builders and enthusiasts have long debated the best way to apply thermal paste to a CPU, and how much thermal paste we should apply. There are a ton of ideas and methods, but we think the easiest way is the classic pea-sized drop. Take your thermal paste and pipe out a small amount of paste in the center of your CPU, about the size of a small pea.
Don’t worry too much about any thermal paste trails when removing the applicator. Sure, they may look a bit ugly, but thermal paste isn’t electrically conductive. So it won’t cause any short circuits.
Once you have the paste on your CPU, it’s time to mount your CPU cooler. If you’re re-using your old cooler, then it’s just a matter of plugging the CPU cooler fan in and screwing the heatsink back on. If you’re swapping to a new cooler, you want to make sure you’ve installed the required mounting hardware.
The pea-sized drop we recommend may not seem like a lot of paste, but your CPU cooler’s mounting pressure will spread the thermal paste out to cover most of your CPU’s integrated heat spreader. You can apply your thermal paste in other ways, such as the “X” method, but there’s little to no difference between all the popular thermal paste application styles.
YouTuber Tech Illiterate tested this out a few years ago and noticed only a 0.5-degree Celsius difference. That’s small enough to be within the margin of error.
So don’t worry too much about applying the correct amount of thermal compound. If your CPU isn’t spiking to 80 or 90 degrees at idle or under light loads, you’re fine.
Knowing how to clean thermal paste off a CPU is essential for any aspiring PC enthusiast. Thankfully, it’s not hard to learn and impossible to forget. Once you’ve done it once, you’ll be able to do it easily whenever you need it.
Have a freshly-cleaned CPU and are unsure what cooler to go for? Check out our liquid cooler vs. air cooler comparison for some tips.