Make sure your cabling is secure. Try the return again. If you still have no HD channels then by a process of deduction there's something wrong with the aerial and you'll need to speak to whoever manages it.
Hi thanks I was thinking the same now after trying everything else. I’ll let the bad weather subside and try again and then contact the Housing Association about the communal ariel. I doubt I will get much help from them!
DO go over your aerial cables and connections - dodgy leads are the most common issue.
Try alternative fly-leads if of the moulded variety
DO disconnect any hdmi cables from the TV and the device(s) connected to them as cross-interference between hdmi and aerial cables can give the same results.
(Keeping hdmi and aerial cables as far apart as possible is wise and may be all that's needed if you're lucky).
Thanks. I literally had all the HD channels one minute then pulled out the Ariel to do something for one minute then they all disappeared. I don’t have any HDMI leads at all. Neighbours will not be helpful as either very old or not quite there upstairs! Also I think if I hadn’t pulled out the Ariel then they would still be there on my menu so neighbours have probably all still got them.