My very old Hotpoint did not cool fridge until freezer was down to temperature, it had been condemned as thermal insulation had failed, but I used it to brew beer in, when a new batch is started the process produces heat, so new batch went into freezer compartment and the whole unit was controlled by an external thermostat
to 19°C and even when it was running for couple of hours, the fridge never cooled, which was good as once it had been brewing for 7 days heat output reduced so could transfer fermenter to fridge compartment.
I also found before it was used as a brew fridge, that it takes a long time to de-ice the ice behind the cover over the cooling bits, I found propping open door and a fan worked well, not a heater, just a fan, but it could take an hour after all the visible ice had gone, before the ice behind the cover had all melted.
It seems the whole problem was due to the thermal insulation being damaged, likely from new, but since I always de-frosted before calling out the freezer guy, they had not realised the root problem. On the one time I had not got around to de-frosting first, he opened door and with one look condemned the unit. Just lucky it was insured.
