Before you call for a repairperson for your refrigerator, either the one you have at home or a commercial unit in a kitchen or retail store, you might want to check on a few common problems that might be the cause of why it's not working. Some of these causes you can address on your own, although of course some repairs will be outside your area of expertise. Note a few tips for troubleshooting some common problems with a refrigeration unit.
The unit runs for prolonged periods of time
You might note that your refrigerator or refrigeration unit runs for much longer than you think it should; you might hear the motor humming and humming without switching off as it should. One common cause of this is a loose gasket around the unit's door. This gasket keeps the door sealed and keeps cool air inside, but, when the gasket gets loose, brittle, or saggy, it doesn't insulate as it should. The door could be left slightly ajar when the gasket is saggy. In turn, the inside of the unit will get warm and the motor will have to run indefinitely. Check the gasket carefully for any damage or loose areas; glue down anything loose and note if that keeps it in place. Otherwise, have the gasket replaced if needed.
Digital thermostat is flashing or showing strange characters
Many refrigerators today, even those meant for residential use, have digital thermostats so you can more easily maintain the interior temperature. If the thermostat is flashing a certain number, you might check the owner's manual to note if it's trying to tell you about a repair that needs to be made. If the characters don't match anything in the manual, chances are the thermostat wiring needs replacing. It may also mean that the thermostat needs calibrating.
Fails to run
If you've checked the power supply and circuit to the unit, note that there may be an improper level of voltage running to the refrigerator cabinet. If there aren't enough volts of power, the cabinet may simply shut down rather than running intermittently. If there are too many volts, it may also shut down to protect the unit from an electrical overload. Check the owner's manual or note if there is a label on the unit that tells you the voltage needed to run properly. You can then check the voltage of the circuit with a voltage meter and have an electrician change the wiring if necessary.