Re: The code! @ katrinab
People who buy from Currys don't live in very cold climates, and no, Scotland is not a "very cold climate", it is actually incredibly warm considering how far north it is.
OK, lets return to the basics. A fridge should have a temperature of about 4C, a freezer around -18C. On a single thermostat model, the design assumption is that the freezer will be kept within tolerances by the fridge compressor running intermittently, making a series of guesses about the room temperature, fridge vs freezer door openings, the addition of food, the known heat transfer through the insulation at given temperatures.
Now, if you actually have a fridge freezer in an outbuilding, and the ambient temperature is at or below 4C, the fridge will rarely if ever run, and a single thermostat freezer will defrost. If the air temp is below freezing, then the fridge won;t run, the freezer won't come above freezing, but because the freezing temps of food are in the -4-9C range, the food is still too warm and starting to spoil. I've seen this happen many hundreds of miles south of Inverness. Now, in a cold room in a house, you're likely to be well above the 4C, but the problem still exists - if the fridge isn't used as often as the design assumptions, the compressor needs to run less frequently, and the freezer temp rises. On these everyday models, few have got freezer temp alarms, nor any over-ride. Maybe it keeps things frozen, but the temp is going to be well above -18C.
Without a constant cooling load on the fridge of around (guessing) 15W, the compressor doesn't run often enough, the freezer temperature rises and may ultimately defrost. In a warm room, the ambient temperature and heat transfer through the insulation will be enough, but once you move to a cooler room you are relying on any over-provision in the original design assumptions. As I say, I've seen the big wet puddle on the floor, I've thrown away defrosted food, and I've seen it happen to others. Cheap, single thermostat fridge freezers are fine in a warm kitchen - away from that they are not as dependable as many people might like.