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I am using a raspberry pi 3 with raspbian 8 jessie (pixel). I have chromium running in kiosk mode but I noticed that the thermometer appears on the top right of the screen to indicate that the PI is running hot.

  1. How do I disable the thermometer from showing
  2. What is the threshold temperature before the thermometer icon shows and what is the max temperature for safe operation of the PI3 ?

Thanks.

cyberjar09
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    The CPU for the Pi is good up to 85°C, but you should never see it anywhere near that during normal operation. Have you tried right clicking on thermometer icon or looking through the taskbar settings? – Darth Vader Oct 18 '16 at 07:31
  • @DarthVader I cant interact with it, it just hovers over the screen on top of chromium – cyberjar09 Oct 18 '16 at 07:36
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    You might want to give this thread a read: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=162432&p=1051610 – Darth Vader Oct 18 '16 at 07:42
  • @DarthVader thanks for the link.. very informative indeed. I believe it is a combination of JavaScript and the closed black case that's causing the heat to touch 82 C – cyberjar09 Oct 18 '16 at 07:59
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    That thread is I think a bit zany. It should not get that hot web browsing. You should try closing the browser and check the temperature with vcgenmd measure_temp to see what it goes down to. – goldilocks Oct 18 '16 at 08:16
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    I first saw the thermometer over top of xscreensaver (blank mode) on day 2 with my RPi3 while I was recompiling the kernel (make -j4 per the instructions here: https://www.raspberrypi.org/documentation/linux/kernel/building.md). I did, however, have this case on at the time: http://www.canakit.com/raspberry-pi-clear-case.html -- and was running LXDE at 1920x1200 too. – DouglasDD Oct 18 '16 at 09:47
  • @goldilocks so it turns out that when idle with the GUI on, the pi is in the range of 45-50 C. Hence I deduce it is not faulty. The web page that is running in chromium in kiosk mode is very JavaScript heavy and I will need to address that first because htop is showing 3 out of the 4 CPUs at over 70% and the 4th CPU is around 30% which is too intense for 24/7 operation. The system is at a constant load average of over 2.4 (1min). Guess ill need to optimize the JavaScript. – cyberjar09 Oct 18 '16 at 11:07
  • I just ran into this for the first time (I've only had it for 3 days.) I'm building one of those magic mirror things and ended up with 4 or 5 copies of the button polling code running at the same time, along with iceweasel. Those, as I'm thinking about it now, are really tight loops when you're not pressing a button (have to fix that). As I killed them, the temp indicator went away immediately. – Jim Feb 12 '17 at 22:50
  • Thought it was worth adding that I ended up here will doing some multitasking on a raspberry pi, mainly in chrome browser and it started cutting out music, assuming this is the CPU throttle you're referring to. I had the raspberry pi in a case and ran the above command and saw the CPU running at 81°F! I added a small fan (3v to gnd) and have it back down to 43°F. So anywho, thanks for asking this question and this info! – tester Jul 25 '21 at 23:28

2 Answers2

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I don't think that should be happening. There is an explanation of the thermometer icon here updated last month, and it says it comes on halfway at 80°C, when the CPU should begin throttling due to overheating.

enter image description here

Then at 85°C it changes to a full thermometer. However, that is the maximum recommended operating temperature.

The Pi should not be getting that hot unless you are overclocking it or running it in an unusual environment.

You can get the exact current tempterature with:

vcgencmd measure_temp

Maxing out all four cores on a Pi 3 for several minutes, I have not seen it go over 60°C. Admittedly this is without making significant use of the GPU, but I still do not think it should get anywhere close to overheating unless defective or abused.

You could get a heatsink, etc., but it is possible to go far enough down this road to mask the real issue. I have a couple of defective MCUs (not Pis, fortunately) that when plugged in, immediately begin to heat up until they are too hot to touch, even when they are not being used for anything. By attaching a heatsink and a fast, 9-12V fan inside a ventilated enclosure, I can keep the temperature stable enough to use them (i.e., so they do burn themselves out -- a normal microchip should not be too hot to touch), but this is not how they were intended to be used; the reason I have two is the second one was a replacement from the distributor, who admitted the manufacturer said it should never rise over 45°C. Which is no where close to "too hot to touch". After the second one turned out the same way I gave up on replacements, they are < $10 items anyway.

Point being, you might be able to "solve" the problem by cooling but first you should check how bad the problem is. Install htop (apt install htop) and run it in a terminal so you can see exactly what your processor core usage is.

Let the pi sit at around idle for a few minutes; with a GUI going and no web browser open, etc., one core or another may constantly blip up halfway, but at least three of them should be at <= 10% usage. If it is significantly more than this you need to figure that out.

If, after idling for a minute or so, vcgencmd measure_temp command says anything more than 50°C with no heatsink or fan, there is something even more wrong and the Pi may be damaged or defective.

If the thermometer icon comes on but vcgencmd reports a normal operating temperature (really, that shouldn't be more than 45°C at idle), there is probably just a glitch with the GUI. Apparently it can be disabled by adding:

avoid_warnings=1

To /boot/config.txt.

goldilocks
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  • It's not necessarily defective hardware. I was just running a TensorFlow lite application processing an image too big for the Pi (3B). It started swapping, which caused the microSD card to get hot (probably heating the rest of the board). The thermometer icon came on until the 100M swap was exhausted, then after Linux killed the process, temperatures returned to normal. – David C. Mar 05 '21 at 20:13
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I just had a half thermometer while Kodi was doing a large scan of a gigabyte size video library on a usb drive. I have a heatsink installed. I removed the cover on the case, blew onto the heatsink a few times and the thermometer disappeared... I left the cover off for the rest of the scan and the thermometer did not return... I suppose one could consider a well ventilated case. I would not like to run a fan, I like the simplicity of the Pi, nothing mechanical that makes noise and wears out...

Jeffus
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