How efficient is your refrigerator running?
Do you need to replace the old door seals on your refrigerator? Here is a good test to try. Close the door on a dollar bill, if you can easily pull out the dollar, you would benefit from replacing the door seals. This conserves electricity by not allowing refrigerated air to escape from your refrigerator, and will increase the life expectancy of your refrigerator.
The area surrounding the refrigerator coils are typically dirty because it is inaccessible. Dust and dirt build-up will increase energy usage, and could cause the unit to break down. You should defrost your manual defrost freezer any time ice builds up more than a quarter inch. The efficiency drops significantly when this happens.