Monday 14 November 1983 - Ep 2 "The Thirteenth Reunion" - 9.30pm
Monday 21 November 1983 - Ep 1 "Witching Time" - 9.30pm
Monday 5 December 1983 - Ep 4 "Growing Pains" - 9.30pm
Monday 12 December 1983 - Ep 6 "Charlie Boy" - 9.30pm
Monday 19 December 1983 - Ep 5 "The House That Bled To Death" - 9.30pm (*)
Monday 26 December 1983 - Ep 9 "Carpathian Eagle" - 9.30pm
Monday 2 January 1984 - Ep 10 "Guardian of the Abyss" - 9.30pm
Sunday 21 May 1984 - Ep 8 "Children of the Full Moon" - 10.30pm
Sunday 10 June 1984 - Ep 3 "Rude Awakening" - 10.35pm
Sunday 24 June 1984 - Ep 7 "The Silent Scream" - 10.30pm
Sunday 8 July 1984 - Ep 13 "Mark of Satan" - 10.30pm
Sunday 22 July 1984 - Ep 12 "Two Faces of Evil" - 11.00pm
Sunday 29 July 1984 - Ep 11 "Visitor From The Grave" - 10.30pm
*Note: The listing for 19 December 1983 is the only one that does not give an episode title, but as The House That Bled To Death is the only one not accounted for it is naturally assumed that it was the episode aired, and on a personal level it is the only episode I have any recollection of seeing, so it definately aired, at least at some time, and this was roughly about the time (late 1983) that I recall seeing it.
I have no real idea why there is a large gap in airdates between January and May 1984. In Australia traditionally, roughly from November to February, it is a non-ratings period where they often try new shows and maybe they tried HHOH in the non-ratings period initially and then realised it was a better show than just non-ratings "filler", so then moved it to mid-year (the cooler months) which is right in the middle of the ratings period. But even when it was shifted to mid-year it wasn't on every week (maybe they wanted to stretch it out) and Sunday night at 10.30 is hardly a prime viewing slot, at least it wasn't then, so who knows.
Then again after all these years (30+) it probably doesn't matter that much!