vi /etc/default/hddtemp

hddtemp network daemon switch. If set to true, hddtemp will listen for incoming connections.

set RUN_DAEMON="false" => RUN_DAEMON="true"
:wq

then 'service hddtemp restart/start'
it works on my ubuntu 16.04 laptop

from conky.

Usually it helps to see whether conky mentions anything relevant on stderr (i.e. run it in a terminal and see what it says). I believe using netcat would pretty much do the same thing conky does, so can you see if nc 127.0.0.1 7634 yields some result?

from conky.

I did run it from terminal, and it reports what I said in the thread title, sorry for not specifying it.
I tried to run netcat, and it gave me this:
(UNKNOWN) [127.0.0.1] 7634 (?) : Connection refused

After running:
$hddtemp -d /dev/sda

Netcat gave me the temperature and model name of the first HDD, but when I would do:
$hddtemp -d /dev/sdb
It would still show me details about the first HDD which is weird.
Doing
$ hddtemp /dev/sd[ab]
However will report the correct data on both HDDs, so there might be something wrong with the daemon. I've triple checked, the hddtemp config file is set to run as a daemon, permissions are set correctly, I tried to restart the daemon countless of times, but it still won't work.

from conky.

I don't think hddtemp /dev/sdb would talk to the daemon and I'm not sure
specifying a disk in combination with -d does what one would expect. So
just to be sure it's actually running as daemon and listening on the port,
does ss -tnlp (or netstat -tnlp if you don't have iproute2) show hddtemp? If
so, what address and port?

from conky.

Nope, strangely hddtemp does not pop up, the configuration file is set for hddtemp to run as a daemon, even tried to do invoke-rc.d restart hddtemp after modifying the config file. I really have no idea why it's not working, but it's clear that it's not a conky issue.

from conky.

Check that hddtemp is still running. In the latest Debian, it sometimes shuts down itsel (confirmed bug), thus Conky can't access it.

from conky.

Chalking this up as an odd case and move on. Also, ${hddtemp /dev/sda} work okay for me.

from conky.