Used Refrigeration Units
Used refrigerators can be a great deal. Before buying, make sure that there are no major problems. Compression or coiling problems are very expensive. Most people sell refrigerators when they upgrade to a newer model. They also sell them if they are moving. With a few quick checks, you can feel confident in purchasing a used refrigerator.
There are some things you will want to check for before buying. One important item you can't check is the compressor's life. The compressor is essential for the refrigerator to work. With a used refrigerator, there isn't a way to know how much life is left in it. Everything else can be checked by a regular consumer. If possible, request that it be plugged in before you arrive to check the cooling system.
Cooling
Plug in the refrigerator. It should cool to a temperature of 38-40 degrees. The freezer should be 0 degrees. Check to make sure that it turns on and off. You will also want to make sure there is a temperature knob to adjust it inside your refrigerator and freezer.
Noises
Listen to see if you hear any loud noises or rattling. A refrigerator should have a quiet hum when the motor kicks on. If there are any unusual noises, ask the seller about this.
Parts
Check if all the shelves are in the refrigerator. Ask about any additional parts if they seem to be missing. Mark sure to check and see if the light comes on. If not, the bulb is easy to replace. Inspect the door to make sure it has a good seal.
Cooling Coils
Inspect the back coiling coils. Make sure you don't see any leaks or damage. Any hissing noises could signal a tiny leak. These are important to the refrigeration process.
Electricity Use
Keep in mind older refrigerators use more electricity. Newer models are energy-efficient, and use 1/3 less electricity.
Owner's Manual
An owner's manual is helpful at identifying what parts you need to replace a light bulb, shelf, etc. Many older refrigerators might not have this. Look at your refrigerator to find the manufacturer name and model. Then go online to their website. If they don't have it listed online, shoot them an email asking how to obtain an owner's manual.