Bush fridge freezers

Make sure the shelves and drawers are well inside the door and it closes properly, make sure the room it's in is not too hot.

Be sure the drain is clear these are well known for drain blockage. the area behind the shelves is where you would find the evaporator and drain hole.

"Always disconnect power before trying to repair any appliance."

Is it just the freezer section? Open the freezer door for a minute and then, without shutting it, press the button on the inside that makes the light go out. The fan at the back at the top of the freezer should start whirring. This circulates the freezing air. If it doesn't start then that's your problem as the freezing air isn't getting to the top of the freezer. It's simple enough to replace. Buy a new part (30 pounds?) and replace from the inside by removing the back panels to the freezer. Turn the freezer off and unplug first though, obviously! Hope this helps.

to connecting arthin wires.

Your fan unit is blocked, draws freezer air from freezer, may be defrost element or defrost timer, needs service machanic, sorry. Russ

just to be sure that your door is sealing properly, put a flashlight into the freezer and turn off all of the lights in the room to see if there are any openings in the seal. Iam suggesting you this coz sometimes a small opening may pass our eyes easily....

if the door is sealing properly......
If this is the type of freezer where the shelves are the evaporator coils, the coolant goes through the shelves(tubing) and the formation of frost is normal and has to be manually defrosted.All the shelves should be as cold asd the top one. The fact that just one has any frost may indicate that it is low on freon. If this is the case you should notice that the freezer doesn't get cold enought just like you said... so check your freon levels.

This could also be because of the thermostat not sensing when the fridge reaches its set temperature and as a result of this the compressor will keep on running and build-up of ice will occur.

Follow the advices in the order prescribed above and you should be set

Check gasket on door. Air may be getting in.

sounds like the defrost drain is froze up use hotwater and blowdryer

you may want to seal up that split with duct tape to make sure water doesnt get in there again, then im sure it will be fine