Hotpoint Frost-free freezer FZA31P. Red light problem

Hi, my mother has a Hotpoint FZA31P freezer (about 3 years old I think). A couple of days ago, an intermittent problem started – it switches itself off. I noticed the red light (“High temp”) LED was on, checked the contents – they were just starting to defrost: firm, not hard but not squishy (managed to transfer them elsewhere). The freezer was silent. During the day the temperature went up to about +3 or 4C.

This lasted all night, then for no apparent reason it started up again in the morning and went cold. Cautiously I put just a couple of pints of milk in. This was OK for a few hours and froze the milk. Then, red light came on again, and it had warmed up. I pulled the freezer away from the wall (there’s a gap of about 5cm all round the box) and had a look at the works. Couldn’t see anything apart from a few bits of verdigris on a thin copper pipe. In fact I was very surprised at how clean it all looked – the drip tray (I suppose that’s what it was) seemed perfectly clean and white, no trace of mould, or scale or anything. Nothing seemed to be hot to the touch.

I’ve double-checked that the door is closed properly (on this model it’s quite easy to leave the door open a bit).

Since then it has been coming on for a few hours then going off again, even empty and with the door not opened. There doesn’t seem to be any water leaking or ice build-up anywhere that I can see (or hear!).

Any ideas?

Thanks.