MacBook Air fan running constantly and causing battery drain

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Level 1

5 points

MacBook Air fan running constantly and causing battery drain

The fan has started coming on 10 minutes after switch on when things are not hot at all. But then the fan being on makes the battery work harder and it does get hot after a while. It was switching off when i close the lid, but now it has started needing a full shut down to stop the fan running. I want to get it fixed before it causes a complete shut down, but as a writer, being without it is like being without both arms...

[Re-Titled by Moderator]

Original Title: I think the fan needs replacing on my MacBook Air - can this be done while i wait if i book in?

MacBook Air 13″

Posted on Sep 9, 2025 3:13 AM

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Answer 1

Top-ranking reply

neuroanatomist

Level 9

56,505 points

Sep 9, 2025 12:00 PM in response to BigSys

Chrome is a notorious resource hog on Macs, in part because of all the background extensions that install along with it, and run in the background even if you aren't running Chrome itself (because Google's main revenue stream is selling user data). If you don't absolutely require Chrome for some reason, I'd suggest uninstalling it. If you do absolutely require Chrome, consider using Brave instead (same code without the Google baggage).

https://chromeisbad.com/

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Answer 2

Sep 9, 2025 8:59 AM in response to BigSys

The fan comes on when the processor temps get high (not necessarily the case temps), not the other way around. Most likely, there is a background process running that is driving your processors. Check Activity Monitor > CPU tab, sort by % CPU to see what is using significant resources.

Activity Monitor User Guide for Mac - Apple Support

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Answer 3

Sep 9, 2025 12:20 PM in response to BigSys

Chrome is an easy one to test by uninstalling and seeing if the problem is resolved. Note that Google usually installs about 3 different processes that run on startup that are not removed by simply dragging Chrome to the trash. Those are in your launch folders and run whether Chrome is open or not.

A good way to check the processes that run on startup that may be contributing to the CPU usage is by posting the free EtreCheck report using the Additional Text option when posting. The report contains no personal information.

How to use the Add Text Feature When Post… - Apple Community

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Answer 4

BigSys Author

Level 1

5 points

Sep 9, 2025 11:47 AM in response to neuroanatomist

Thanks for this - I'd not thought to check. The highest usage seems to be Chrome that verges between 5.1 and 9.7 so I don't imagine this is the problem is it?

Incidentally, the case is not usually hot when the fan comes on, but it does become uncomfortably hot within an hour, by which time the battery has reduced by half.

Other suggestions are definitely welcome - thank you.

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