Common Refrigeration Issues and How to Fix Them

Commercial refrigerators are critical for continuing daily operations in supermarkets, convenience stores and restaurants. Regardless of size and capacity, every commercial cooling unit operates according to the refrigeration cycle, so the problems that arise are similar across all machines. While commercial refrigeration repairs should always be completed by a licensed, qualified HVAC contractor, it is helpful to understand the nature of the most common issues. Communicating valuable information to the service tech can help save time and money.

Compressor Malfunction

The heart of every refrigeration system is the compressor, which transforms low pressure gas into a high pressure gas as it enters the condenser. When the compressor malfunctions, the unit will not cool properly. The symptoms of a compressor problem include insufficient cooling, temperature fluctuations, unusual sounds from the unit, an excessively hot surface and repetitive unsuccessful attempts to start the motor.

Compressor service includes using a set of refrigeration gauges to measure the discharge and suction pressure, which can expose improper refrigerant charge issues. Other compressor-related problems include burned or disconnected motor windings, blown fuses or an electrical fault. Compressor testing is one of the many refrigeration services included in a commercial maintenance agreement.

Temperature Fluctuations

Temperature fluctuations are costly since refrigerated merchandise can spoil quickly. A performance check with proper gauges can confirm if subcooling and superheat are within normal operating parameters. If the integrity of the refrigeration cycle is confirmed, there may be issues with the controls in the system.

If the unit will not run at all, the thermostat may be stuck in the open position. A technician can test the unit by detaching the wires from the thermostat and connecting them directly together. If the unit runs after the breakers are engaged, the thermostat needs to be replaced. If the unit runs all the time, the thermostat may be stuck in the closed position. The same procedure as described above can be used to test the device.

Fan Motor Failures

Fan problems interfere with the proper movement of conditioned air, so it is important to make sure there are no airflow restrictions in the system. There are two fans in commercial refrigeration equipment. The condensing fan is located on the condensing unit and is used to exhaust heated air extracted from the refrigerated area. The evaporator fan is installed inside the interior of the unit and is always positioned near the top of the box.

Regular cleaning of the coils will eliminate potential restrictions and help keep the fan motor from burning out. If the fan isn’t working, a volt meter can be used to confirm whether the unit is receiving power. Most fan problems result from faulty wiring or a burned out motor.