Fridge freezer not cooling down properly?

Hotpoint
Frost-free fridge freezer, 2 years old.
RFA52

A couple of weeks ago the fridge started to ice things over, even thought the temperature was on 4/5. I tried lowering the temperature to 3/5 but there was still frost.

Then two days ago both the freezer and the fridge started to warm up to the point where they were both room temperature. The light is still working and the motor is still whirring.

I cleaned the condenser coils last night with a paint brush (there was minimal dust), and when I checked the fridge this morning, the freezer part was working, and the fridge had frosted up at the back, but it was still relatively warm for setting 4/5 and fast freeze.

Any ideas?

Thanks in advance...fingers crossed !

James
January 2010