Gotta love natural Canadian cooling.

And it isn't even winter yet. If you're wondering, temps are showing 0 because S4's temp sensors don't register below 20c.
Your HW Error is rather high.. and do you realise you have have a X on one of the chips?
Hard reset for that. I had one and a soft reset just makes it worse

Talking about that... my chain 1 goes offline after about 1-2 days running, sometimes in a matter of few hours. GUI will be reporting as if nothing wrong. You'll only notice when your hash rate at pool end drops. You can also look into the casing via the fans, you should be able to see 4 red leds if all chains are running. Was thinking of taking the S4 to a host but with me constantly having to look to see if there is 4 red leds, not going to be possible. Plus having to hard reset when you get "Hugs & Kisses".. makes it even more impossible to have the S4 hosted.
Could it be a firmware issue or hardware?
Hmm wonder if that is what happened to me. After running flawlessly for 22 days on Sunday one of my S4's dropped to only 1.2-1.3ths, checked the gui, all chains reporting good and still have CK's fix applied so wasn't a power glitch causing a full reboot. Did a soft reboot, reapplied CK's tweak and came right back up to full speed. I do still suspect power so have an always on-line ups coming for it just to be sure. So far it is only the S2 and S4 Beaglebone based miners that have been needing the ups's, S1 & 3's seem to handle power dips just fine
If it happens again I'll check the activity lights.