How to Clean Thermal Paste off CPU [2023 Beginner Guide]

Many people assume that just because they’ve built a PC and got it to boot, that means the job is done. Now they can leave it alone to run in peace, yes? Well… yes, but also no. You can definitely be comfortable with a newly-built (or even a not newly-built) computer for several months, but there will come a point where it starts slowing down -- that may be the time to replace your thermal paste. In this quick guide, we’ll explain to you why you need to replace your old thermal paste, how, and what the best way to do that is.

Why do we need to clean old thermal paste?

It might seem like a no-brainer to some, but others still don’t know that you need to clean off old thermal paste before putting in a new dab. They may also be confused as to what the exact reason is. I mean, they’re both thermal pastes, right? They should work together.

Not so. You see, thermal paste is not infinite in its use time. It degrades over time (usually a period of a year or two) and becomes ineffective. So even if you were to put new thermal paste atop the old, the old thermal paste -- which has since lost its ability to transfer heat -- would bring down the overall heat transfer efficiency.

And essentially, that’s what it’s all about: Heat Transfer Efficiency. The end-goal of applying or reapplying thermal paste is to gain an efficient transfer of heat between your CPU ILH and the heatsink. Having a consistent spread of one brand of thermal paste which was all applied at the same time raises that efficiency to its maximum. Leaving the old one would do nothing but bring it down.

What to clean thermal paste with?

So now that we know why we need to clean off old thermal paste, let’s address the how. If you’re unaware, cleaning thermal paste is not like cleaning toothpaste or spilled tomato paste. Namely because those two are seldom-used with computers. Yes, we know toothpaste works as a short-term thermal paste. No, we still don’t recommend it.

To clean off old thermal paste you can use:

●       Rubbing alcohol (mainly isopropyl-based, whereas normal alcohol is ethanol-based)

●       Lint-free cotton swabs

●       Lint-free paper towels

●       Specially-designed cleaning wipes

When working with computers or computer parts, it is not recommended to use water in the cleaning process. Though in rare cases people do use distilled water for deep-cleaning, rubbing alcohol is a much better substitute. If any bit of moisture is left on your motherboard or CPU after the cleaning process, it could render your parts useless and cause the solder in them to corrode. Alcohol dries quickly and doesn’t leave any traces.

Of course, you don’t want to only use rubbing alcohol; you also want something to be able to wipe to remove the old thermal paste. In this case, you can use either a lint-free cotton swab, or a lint-free paper towel. Why lint-free? Lint (little pieces of cotton or paper) can get stuck to the old thermal paste or spread out onto your motherboard which may cause damage to electronic components or lower the overall efficiency of your computer. That means no toilet paper.

For this reason, we personally recommend using specialized thermal paste cleaning wipe. You won’t need to worry about spilling alcohol onto your motherboard or CPU and you won’t need to check whether the tool you’re using to scrub leaves lint. They also come prepared with a specially-designed ingredient that enhances cleaning performance better than rubbing alcohol. Thermal paste cleaning wipes are the quickest and most efficient way to clean old thermal paste off your CPU.

Best way to clean thermal paste

The best way is, of course, using the specially-designed thermal wipe. For 2 reasons:

1.      The special substance applied to the wipes is better than rubbing alcohol at cleaning off old thermal paste.

2.      It’ll save you time and effort to open up a thermal paste wipe rather than trying to get the swabs and alcohol together and checking if they’re safe to use.

 Kooling Monster KLEAN-01 is the thermal paste cleaning wipe with super cleaning performance that we highly recommend using to clean off thermal paste.

The 6 easy steps to cleaning are:

1. Remove the cooler from the CPU (if you have a water-cooled PC, this would be the waterblock)    

2. Wear gloves and open thermal paste cleaning wipe (or use alcohol/cotton swab/paper towel combo)

3. Use the thermal paste wipe to wipe the old thermal paste off the surface of the CPU

4. Use the thermal paste wipe to wipe the old thermal paste off the surface of the heatsink

5. Polish the surfaces one more time with a new thermal paste wipe to make sure there’s no excess left

6. Wait 2 minutes for it to safely dry

Now one more time, with pictures:

Wrong way to clean thermal paste

While there’s a “best way”, there’s also a “worst way”.

The worst way is not cleaning it at all. Remember that not cleaning off your old thermal paste will influence the heat transfer efficiency between the CPU and the heatsink. This means all the heat your CPU generates won’t make it out of the CPU, much less the case. This will make your computer run slower over time and possibly even cause abrupt shutdowns later in the future! Yes, it’s that important.

The second worst way (or wrong way) would be to use low-quality rubbing alcohol. If you choose to use rubbing alcohol, make sure it is specially-bought for cleaning computer hardware. That means no diving into your liquor cabinet for the vodka. It’s tempting, we know. But trust us -- lower quality alcohol can leave impurities or stains on your CPU which will also influence the heat transfer efficiency, as the thermal paste -- no matter how good -- won’t be able to interact with the surface of your CPU correctly.

FAQ

Why is it crucial to remove old thermal paste before applying a new one?

Removing old thermal paste is crucial because it degrades over time, losing its ability to effectively transfer heat. Layering new paste atop old, degraded paste reduces overall heat transfer efficiency, undermining the purpose of thermal paste.

What materials are safe to use when cleaning thermal paste off a CPU?

Safe materials for cleaning thermal paste off a CPU include isopropyl-based rubbing alcohol, lint-free cotton swabs, lint-free paper towels, or specially designed thermal paste cleaning wipes. These materials effectively clean without leaving residues or causing damage to electronic components. View more about KLEAN-01🔗

Why shouldn't I use water or low-quality alcohol to clean off thermal paste?

Water is not recommended for cleaning off thermal paste as it can leave moisture, potentially causing corrosion or damage to electronic components. Low-quality alcohol may leave impurities or stains on your CPU, which can negatively affect the new thermal paste's heat transfer efficiency.