Imac 2020 fans constantly running

Getting rid of the fearware is the best first step. However, there are other general factors that affect temps and therefore the speed of the thermostatically-controlled fans.

1—"Piggy" web pages: I have a fan control app on my 2017 iMac and, with only these forums open in about a dozen tabs, CPU temps showing 38-40°C at slowest fan speed (1200 rpm on my model). If I open some sites in the background, temps will go to 55-60C in minutes and the fans will ramp up. Activity Monitor will show you which sites are the fat hogs. Several election night results sites did that to me in 2020.

2—Spotlight activity: Your report does not suggest this an issue now, but it can happen. You can use Spotlight settings to limit what items it indexes. By default it indexes a laundry list of items, many of which do not need indexing or can be searched within an app. Use Settings to reduce the number of items for which you search:

Spotlight settings on Mac - Apple Support

3—Workspace: Did something physically change that may have effected cooling efficiency? A user posted this image here when describing overheating of an iMac and asking why:

The image alone answered his question. For years iMac have taken in cooling air through vents on the bottom edge of the display. The user blocked about 80% of the air intake capability. Space between the work surface and the bottom edge of the computer must be respected.

Another cooling problem reported here, and one I am able to duplicate like a party trick on my iMac 27 5K, is tipping the display too far forward. At the Altar of Minimalist Design, in 2012 the iMac hot-air exhaust vent was moved from above the stand hinge to behind it, like this:

When the display is tipped fully forward, it is very close to the vent, slowing the expulsion of hot air and causing elevated temps inside.

4—The easy one. Have you cleaned the air intakes lately?

Try the following: reset the SMC two or three times in a row: How to reset the SMC of your Mac - Apple Support.  Be sure to disconnect all peripherals before resetting the SMC. 

If the above doesn't help please post the Etrecheck report with your reply according to these directions:

Copy the report as shown in this animated screenshot

and use the Additional Text button to paste the report in your reply.

Then we can examine the report and see if we can determine the cause of the problem.

First thing to do, is reset the iMac's SMC and NVRAM.

Reset the SMC of your Mac - Apple Support

Reset NVRAM on your Mac - Apple Support

Then if that does not calm things down, post your EtreCheck Pro report.

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

1) macOS does not require any third-party security app's like Trend Micro. see > macOS - Security - Apple

I suggest that you uninstall Trend Micro as per the developers instructions.

see > https://helpcenter.trendmicro.com/en-us/article/tmka-14475

2) MacFanControl is a great utility and I run it on all of my Mac's. see > https://crystalidea.com/macs-fan-control

Problem is that if it is not set properly, then the iMac's Fan will constantly run faster than the default speed.

If you are having trouble setting it up? see > https://crystalidea.com/macs-fan-control/fan-presets

Have you tried a reboot?

Have you tried Safe Mode?

Start up your Mac in safe mode - Apple Support

Thank you for the EtreCheck report it is very helpful and points to some very serious things that are wrong with your computer and causing issues. First, there is no evidence that you backup the computer. If this is correct then that is a HUGE error and a 100% guarantee you will lose data. If you are not familiar with Time Machine please refer to Back up your Mac with Time Machine. Doing a proper backup will require an external HD, what many experienced users on these forums prefer is the OWC Mercury Elite Pro. A 1-2 TB model would be fine for your needs. Backing up should be your #1 priority.

Next is what has been installed on the computer is causing a mess!

I see some issues in your report. First is you have TrendMicro and some third party VPN apps installed which is considered malware by most experienced users on these forums. Mac OS is catlike in that it cleans itself, Mac OS does not benefit from nor does it require any of the following types of third party apps:

·      Antivirus Apps

·      Cleaning Apps

·      Security Apps

·      VPN Apps

·      Maintenance Apps

What these types of apps do is the exact opposite of what users want. They make Mac OS slow, appear buggy, can damage Mac OS and sometimes create unwanted behaviors. In short, they are really bad news! Also, I am pretty certain they are at the root of what is causing issues with your Mac!!!

So the first order of business for your computer is that you need to locate the developers. uninstall instructions for Trend Micro and the VPN apps and please uninstall them. Because TrendMicro is pretty nasty stuff it tends to leave parts behind after being uninstalled, a testimony to how poorly written the app is! To fully ensure you have uninstalled it please download the free version of FindAnyFile directly from the developer. Then have it search your system for the following:

·      TrendMicro

·      ProtonVPN

Have it Trash anything with those names in them and then ensure the Trash has been emptied. Then run a new EtreCheck report and post it here. We can then look it over to see if there is any evidence of those apps still being installed.

To add to rkaufmann87's recommendation you can check to see if you've removed all of the supporting files by downloading and running the shareware app Find Any File to search for any files with the application's or the developer's name in the file name.  For software in question you'd do the following search(es): 

1 - Name contains proton

2 - Name contains vpn

3 - Name contains trend

4 - Names contains micro

Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.

FAF can search areas that Spotlight can't like invisible folders, system folders and packages.  

If you get warnings that the file can't be deleted because it is in use or used by another app boot into Safe Mode according to How to use safe mode on your Mac and delete from there.

Note:  if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode.  This makes it act as a wired keyboard as will assure a successful boot into Safe Mode.

Please post some screenshots of your current MacFanControl panels and settings.

I use the Sensor-based value to slowly increase the Fan speed as the temperature goes up.

1) my Sensor-based value is set on the CPU PECI

2) the start to increase is set at 120 F

3) the max is set at 195 F

Thanks for the new EtreCheck report, as you mentioned ProtonVPN OpenVPN is still installed and needs to be fully uninstalled. Another thing  you can check is if you have any third party peripherals connected to the computer via USB (printers, scanners, external HD's, hubs etc.) please disconnect them and then test again.

To get rid of any remaining Proton VPN and Trend Micro Files, try running FindAnyFile again and see if they will remove them. If not then contact the developers of the apps and ask for support on how to remove all of the app. If they cannot (or will not) do that then you may need to manually locate each file and remove them. Failing doing that then the only thing left is to do an erase and install and start over.