[BoxFreak]

I´d like to find out why some of my timed recordings fail. Is there a log that tells reason for fail (eg. my PC didn´t start or something else)?

[Prof Yaffle]

All recording activity is sent to syslog by default, so start there. You can also switch debug logging on in a variety of ways, starting with the up arrows and cog in the bottom-right of the web interface or editing /etc/default/tvheadend (distro dependent) - if we need to go deeper, then you're into trace logging and similar, so let's leave that for now.

Check syslog. Post the output and I'll take a look, or post it on tvheadend.org, or try IRC #hts.