Hoover WF568A frost free fridge freezer

Hi all,

We have a Hoover WF568A frost free fridge freezer that's 2 years old,
we have noticed noises coming from the back "sounds like ice cracking"
and a few days ago it started defrosting.
I turned it off for around 10 minutes and back on again and it started working but not as it should be, luckily it's still frozen in the freezer and the fridge is still cold but it seems to be struggling to keep cold and the noises from the back are still their, we called a hoover approved engineer and i suggested that the hot weather might be a problem, he agreed and said leave it for a couple of days, but now the weather is cooler it is still struggling to maintain a regular temprature and always looks like it's on the brink of defrosting!
any help is greatly appreciated.

empty fride and freezer completely un plug it and satrat again.

I do it to our fridge and frezzer about once a year

if not call hoover again