Thanks for the replies. 99% sure door seal is good and it is closed. (checked that).
There is little water in the drain pan at the back so freezing is a possibility.
The freezer is a slide out which is bigger pain to get into than the door I had left at the other house. It had a similar problem but was iced up behind the plastic panel on the coils. It needed some timer, but the repair man fixed that one.
Going away tomorrow (holiday) so the fridge is waiting a few weeks until get some time to look at it unless it breaks worse than it is now
Brad