The refrigerator is a relatively simple machine. However, there are some large main components that eventually fail. Many common causes of inefficient refrigeration have to do with the wear on the motors and electronics not working properly within the unit. Refrigerators are extremely susceptible to this wear and tear because it is one of the most heavily used appliances in the household with motors constantly running trying to keep a the compartment of the unit at a given temperature. If your refrigerator is not working or not cooling here are a few things to look for to help diagnose your problem.
-Are your lights shutting on and off?
-Is your Sub-Zero running hot?
-Is your unit making excess noise?
-Is your Sub-Zero running all the time?
-Is your refrigerator leaking or is moisture constantly forming?
Many times can an unattended to small problem create much larger issue within a refrigerator. Take for example a recent customer who had two appliance companies misdiagnose an issue with a Sub-Zero™ 532 model side-by-side refrigerator. The unit was running all the time, never really shutting off. Two service companies replaced fan motors and thermostats, completely ignoring something much more minor at the root of the problem: the light switch. The lights would not shut off when the door closed, so it over-heated the thermostat, tricking it into leaving the compressor for many hours at a time, eventually overheating the entire unit.
The only possible way to avoid repair on a Sub-Zero™ not working is to clean the condensor regularly, as well as have a trained technician come to your home to grease and test all functions of the machine. This should be done every few years to make sure your refrigerator is cooling properly and not wasting electricity.