I have a hotpoint ff 175 bp and the temperature dial on the fridge has staerted to make an annoying and very loud constant buzzing sound with only stops when it is switched to zero.. which is no good because then the fridge is off ?? any ideas ?

You will have to dismantle the control box and see if the buzzing is coming from the cold control or from a defrost timer which is usually in the same area and is more commonly the cause of a loud buzzing. Whichever one it is you have to replace it right away. This is not a complete model number so if you need more help then post a full model number. Good Luck Appliance Specialists