Listed below are the 6 most common conditions or parts that may cause a commercial refrigerator to build up with ice or freeze food. They are:
Temperature Control Thermostat
A defective temperature control thermostat may be the reason for your refrigerator freezing food. Power flows through the condenser fan, evaporator fan and compressor because of the thermostats. Rotate the temperature control thermostat all the way and listen for a click as you do so from stop to stop. If you hear a click, it may be fine but if there’s no click, remove it and check for continuity. If it’s calling for cooling, it has continuity.
A defective thermistor, the sensor connected to the control board that monitors air temperature, may be the reason your refrigerator is freezing food too. The refrigerator may cool continuously or not cool at all if the thermistor is faulty.
Temperature Control Board
The temperature control board, which provides the voltage for the compressor and fan motors, may also be faulty if the refrigerator is cooling food. Be sure to check every other component to be certain this is the cause of the problem as these boards are often misdiagnosed.
Main Control Board
This is not common but the main control board may be defective if your refrigerator is freezing food. Examine the defrost system, fans, damper, and thermostat first.
Damper Control Assembly
If the air damper control is broken or stuck open, your refrigerator will freeze food. The damper is either a manually or automatically operated door which closes and opens to allow less or more cold air get into the refrigerator compartment. Not opening properly means letting too much cold air into the refrigerator.