USG Flex 700h - Fans/Temp Management

JS87

Hey Zyxel Team!

I love my new 700h in my Homelab, but please please adjust the fans.
They are spinning 10sec. normal, then 10sec. high and that on repeat.

My CPU is at 12% and Memory on 59%.

It wouldn't be a problem when it's an high permanently, but that normal/high switch every 10s is a little bit annoying.

But so far it's a great device :)

Zyxel_Kay

Hi @JS87

Thank you for your feedback, and we’re pleased to hear you’re enjoying the USG FLEX 700H in your homelab! We’d be happy to take a closer look at the fan behaviour you described.

Could you please provide us with the following details?

1. Firmware Version: What firmware version is currently installed on your USG FLEX 700H?
2. Temperature and Fan Speed: Could you record the temperature and fan speeds during both the normal and high-speed cycles? You can find guidance on checking the CPU temperature and fan status via CLI here:
   How to Check CPU Temperature and Ensure Proper Operating Temperature [USG FLEX H]
3. Environment Temperature: What’s the approximate ambient temperature in the area where the device is set up?
4. Video Recording: If possible, could you capture a short video (with sound) showing the fan noise pattern? Please feel free to send it to us via private message for closer review.

Thanks for helping us with these details! This information will enable us to better understand the behaviour and offer further support.

JS87

Hi Kay!

Thanks for your reply!
When I came home after work, I turned on several more devices and the CPU went up to 14% and since then, the fan stays the same :/. So I guess the values don't matter at the moment:

1. It is the latest V1.30(ABZI.0)
2. Sensors[0]:45 degress C
   Sensors[1]:40 degress C
   Sensors[2]:54 degress C
   FAN[0]:2592 RPM
   FAN[1]:0 RPM
   FAN[2]:7346 RPM
   FAN[3]:0 RPM
3. Between 22 and 24 degree Celsius and humidity is at 45%
4. https://www.youtube.com/watch?v=VVqjhGDgy98

I'll repeat the steps 1-4, when the fan starts again!

JS87

I was able to track it now with the CLI:

usgflex700h> cmd fan-get
Sensors[0]:45 degress C
Sensors[1]:40 degress C
Sensors[2]:54 degress C
FAN[0]:2728 RPM
FAN[1]:0 RPM
FAN[2]:7769 RPM
FAN[3]:0 RPM
usgflex700h> cmd fan-get
Sensors[0]:46 degress C
Sensors[1]:40 degress C
Sensors[2]:55 degress C
FAN[0]:2597 RPM
FAN[1]:0 RPM
FAN[2]:7346 RPM
FAN[3]:0 RPM
usgflex700h> cmd fan-get
Sensors[0]:45 degress C
Sensors[1]:40 degress C
Sensors[2]:54 degress C
FAN[0]:3428 RPM
FAN[1]:0 RPM
FAN[2]:7769 RPM
FAN[3]:0 RPM
usgflex700h> cmd fan-get
Sensors[0]:45 degress C
Sensors[1]:40 degress C
Sensors[2]:54 degress C
FAN[0]:2597 RPM
FAN[1]:0 RPM
FAN[2]:7346 RPM
FAN[3]:0 RPM

JS87

Now you can hear it in the YT-video

At the moment of filming, it were 22°C and still 45% humidity

Zyxel_Kay

Hi @JS87

Could you please also download the startup-config.conf file from your device and share it with us via private message? We'll review your configuration and attempt to replicate the issue in our lab environment.

Additionally, we’d appreciate it if you could provide the traffic usage data (throughput, session count, etc.), which you can find on the device's GUI dashboard.

Zyxel_Kay

Hi @JS87

Thank you for providing the detailed information and remote GUI access.

We’ve reviewed your device configuration and closely monitored its status during the remote session. Here’s our conclusion: the behaviour of your device is as expected. Since the Sensors[2] is located near the 10G module, the fan RPM will remain high even if traffic levels are not particularly high.

Regarding the noise occurring every 10 seconds, this is due to changes in fan speed and is normal behaviour, so it’s not a cause for concern.

JS87

Thank you very much!
But wouldn't it been better, when the next firmware realise there are SFP+ modules active and then prophylactically turns the fans a lil bit more, instead of that switching between some values from real time information?

At the moment it's switching between 5600 and 5900 which aren't annoying values when they would stay, but that switching every 10s isn't what I expected 🙈

P.S. I had a new customer today because nobody wanted to manage their old ZyWall 310. We are going to replace it with a Zyxel 500h :)