To check that your refrigerator freezer isn't working, you'll need to first plug it into the wall and leave it for a few hours. By this point, the appliance should start to get cold. If it doesn't then there may be something wrong with either its thermostat or compressor - in which case you would need to call out an engineer. If your refrigerator-freezer does seem like it's working okay but isn't keeping things cool then you could try the following: Check to see if there's any ice building up on the back wall - this could indicate that it isn't pulling in cold air properly. Just wipe away any ice so that it doesn't start dripping onto other items inside your freezer and causing further damage. Another issue may be caused by dirty filters. Sometimes the refrigerator freezer will be pulling in too much air and this can cause a drop in temperature. Check to see if there's any residual ice remaining from when your appliance was packed - you may need to let it melt before using but do make sure that water isn't dripping onto other items inside of your fridge freezer because this could damage them too. If you have a glass door, check to see if it's covered in condensation - this can indicate that your thermostat needs adjusting so try turning it up a notch and seeing if the problem disappears.