I tried to record the FIM Superbike World Championship on wed morning 03:10 - 03:35 and added 5 mins padding to the end. The recording had failed 'unknown reason' and indeed it had. It started on time but stopped at 03:30, so I set another timer for this morning same time also on CH4 and that did exactly the same thing, no other timers were set during this period and the HDR was in standby before I went to bed. Could this be related to the house keeper? Would someone like to set a recording of the same time on CH4 to see what happens?
Thanks

Almost certainly it's the housekeeping. Try leaving the hdr on on the nights you want to record around 3 am.

I recorded that early Wednesday morning showing of the WSB highlights on my Foxsat on CH4HD just fine (normally record it on my Freeview PVR but that clashed with the DSO Stage 2 from the Oxford transmitter). I did note that the start unusually was in the opening intro whereas Channel 4 recordings have lately been starting halfway through the ad break which I can assume was due to the short delay caused by the overnight housekeeping. No action missed and the programme ended after showing the race results and championship position.

There is another showing this weekend for the OP to have a go at recording.

Hmm... that's strange then, mine was SD. I know about the repeats but I wanted to record the first showing incase of situations just like this

Actually if the Foxsat has already partially woken up in "listening mode" by the time 3am comes around does it do the housekeeping? Perhaps not. And if you were not using accurate recording but a padded timer (so not in listening mode) this may explain why the housekeeping event happened first on your machine and screwed up the timer due to fire. Which would make my earlier remark about the start of my recording being delayed not right.

With no padding the HDR would wake up 15 mins before and it would skip housekeeping. With padding it would wake up at 03:10 - Less padding = 03:05 (housekeeping starts at 03:00 and takes about 7 mins (depends on how many thumbnails need to be generated, etc).

I know it always catches me out when I am using my Freeview PVR and the audio cuts out for a while as the Foxsat fires up to do its housekeeping (a manifestation of a bug I have previously reported) as my AV amp shares the same logical input between the analogue audio connection from the TV and the digital audio connection from the Foxsat which takes precedence.