Check the power supply to the walk-in freezer. Look in the breaker box to see that the switches to the freezer are on.
Examine the door gasket for “snow” buildup inside the freezer. Open and close the door to see whether it is operating properly. Tighten or replace the hinges if they are allowing air leakage into the freezer. Keep the door closed as much as possible to minimize snow buildup. If the door must be open while you load or unload the freezer, install a heavy-duty strip curtain over the door to minimize the amount of warm air entering the freezer.
Inspect the relief air vent for ice. If the door is difficult to open, a blocked air vent may be the cause. Ensure the air vent has electrical power. Call a service technician if it has power but continues to ice.
Clean the evaporator coil with a vacuum if you see sheets of hard ice developing inside the freezer. Check the drain pan and drain to ensure condensation can flow away from the freezer and not build up inside it. Examine the pipes for leakage. Replace damaged pipes with steel or copper rather than PVC material. Install a drain line heater if condensation freezes before it leaves the freezer.
Watch and listen to the freezer’s motor as it progresses through a cooling cycle. If the motor runs constantly, it may be low on refrigerant. Call a technician to refill the refrigerant.
Check the direction of the fans in the walk-in. If one of the fans is malfunctioning or pointed in the wrong direction, it can put extra stress on the motor. If you think this is happening, call a service technician.