According to repair clinic other possible reasons include dirty evaporator coils a faulty thermostat or a bad evaporator motor compressor.
Walk in freezer evaporator fans not running.
The freezer light should turn off and the evaporator fan should kick on after a few seconds.
The condenser fan motor draws air through the condenser and over the condenser coils.
If the evaporator fan doesn t run in the diagnostic test mode then you could have a defective control board but the problem could also be a bad evaporator fan or a break in the wiring.
If the condenser fan is not running check the fan blades for obstructions.
Let s check the wiring first.
Clean walk in cooler and walk in freezer condenser coils.
Check fan motor and its electrical circuit.
Physically obstructed if the fan is not running unplug the refrigerator and remove the evaporator fan cover.
Next ensure that the blades spin free ly.
In many cases the problem is do to the fact that the evaporator fan cannot operate.
If it turns on you should be able to clearly hear the electric motor activate and then a low hum from the fan spinning.
Not running if the freezer has electrical power the inside light turns on but the compressor won t run a failed cold control thermostat could be the problem.
If your refrigerator isn t getting cool the fan is just one of many possible reasons.
If your freezer has electronic controls instead of a dial a failed relay on the electronic control board or a bad control panel can prevent the compressor from getting power.
Insufficient refrigerant in system.
If the fan motor does not turn on while you hold the switch the motor is probably bad.
A loud blowing sound from the motor doesn t mean it s bad either.
Unplug the refrigerator and remove the screw that holds the control box.
If the fan blades do not spin freely the fan motor bearings are worn out and the fan motor should be replaced.
See corrective steps for low suction pressure.