Thanks everyone for the reports. This is helpful.

Based on what you're describing (CPU temp visible, but no PWM reporting and no fan adjustment), this is almost certainly not a YAML variable issue.

TrueFan relies on standard Linux hwmon interfaces (typically via drivers like nct6775, it87, etc.) to:

On many OEM systems (QNAP, HP EliteDesk, CloudStar J3455, etc.), the fans are:

In those cases, Linux can read temperatures but cannot access or override fan control because no writable PWM interface is exposed.

That would explain:

If you have shell access to the TrueNAS host, run:

ls /sys/class/hwmon/

Then:

for d in /sys/class/hwmon/hwmon*; do
  echo "== $d ==";
  ls $d;
done

If you are running TrueFan in Docker, you can check what the container actually sees:

docker exec -it truefan ls /sys/class/hwmon/

Then:

docker exec -it truefan sh -c 'for d in /sys/class/hwmon/hwmon*; do echo "== $d =="; ls $d; done'

If you do not see files like:

pwm1
pwm1_enable
fan1_input

then the motherboard is not exposing controllable PWM to Linux.

Many NAS appliances and business desktops intentionally restrict manual fan control at the firmware level.

In those cases:

TrueFan can only control what Linux exposes.

If you can paste the output of the hwmon listing above (host or container), I can confirm whether your system supports software PWM control.

This is likely a hardware limitation rather than a configuration bug.

Will not adjust fan speeds on QNAP NAS #4

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