SWMBO noticed the freezer in the Hotpoint FF (largish frost free beastie, about 8 - 10 years old) was getting too warm. Slapped a thermometer probe in there and sure enough its only getting down to about -6C. Fridge seems ok. Compressers is running, sounds normal, and cycling as normal. First thought was it might be the circulation fan in the freezer, but having uncovered that yesterday, it still seems to spin up freely. The other clue is that the rear heatsink coils do not feel warm enough to the touch, suggesting lack of heat pumping.
Any thoughts about things to investigate etc before an expensive shopping trip looms?